Summer X-rays at the NSLS

older
significant figures in reporting...

Robert Sweet

20 Jun 2011 20 Jun '11

10:54 a.m.

Summer X-rays at the NSLS The PXRR operates five beamlines at the NSLS: http://www.px.nsls.bnl.gov/. Two of these are the undulator beamlines X25 and X29. The dipole beamlines X12-B and X12-C are available, and are very effective for conventional crystallography. There are efficient ALS-Style Automounters available -- 8400 crystals mounted in the last 12 months. Also, at beamline X26-C, we have a unique-in-the-US station for combined x-ray diffraction and single-crystal optical spectroscopies: http://www.px.nsls.bnl.gov/x26c/x26c_info.html Notice also our world-leading Mail-In crystallography program: http://www.px.nsls.bnl.gov/Mailin.html You may request access to any of these here: http://www.px.nsls.bnl.gov/beamtime_requests.html, and can look at the schedules for all five here: http://www.px.nsls.bnl.gov/ Stay tuned for the announcement in December of RapiData, our annual course in rapid data collection and structure solving: http://www.bnl.gov/rapidata/ Bob Sweet ========================================================================= Robert M. Sweet E-Dress: [email protected] Group Leader, PXRR: Macromolecular ^ (that's L Crystallography Research Resource at NSLS not 1) http://px.nsls.bnl.gov/ Biology Dept Brookhaven Nat'l Lab. Phones: Upton, NY 11973 631 344 3401 (Office) U.S.A. 631 344 2741 (Facsimile) =========================================================================

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zhangh1＠umbc.edu

20 Jun 20 Jun

11:52 a.m.

New subject: is there any phenix utility that can evaluate the Patterson Correlation function between exp and model data?

Hi, If I only have the experimental and model scattering factors (without model coordinates), is there any phenix utility that can evaluate the Patterson Correlation function between exp and model data? By the way, is the one by FFT as described in (http://www.nature.com/nature/journal/v473/n7348/full/nature09964.html) implemented in Phenix? Thanks a lot! Hailiang

Jacob Keller

1:53 p.m.

New subject: is there any phenix utility that can evaluate the Patterson Correlation function between exp and model data?

I am curious--how did you get model F's without the coordinates? JPK On Mon, Jun 20, 2011 at 9:52 AM, wrote:

...

Hi,

If I only have the experimental and model scattering factors (without model coordinates), is there any phenix utility that can evaluate the Patterson Correlation function between exp and model data?

By the way, is the one by FFT as described in (http://www.nature.com/nature/journal/v473/n7348/full/nature09964.html) implemented in Phenix?

Thanks a lot!

Hailiang

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-- ******************************************* Jacob Pearson Keller Northwestern University Medical Scientist Training Program cel: 773.608.9185 email: [email protected] *******************************************

Nathaniel Echols

2:13 p.m.

New subject: is there any phenix utility that can evaluate the Patterson Correlation function between exp and model data?

On Mon, Jun 20, 2011 at 9:53 AM, Jacob Keller wrote:

...

I am curious--how did you get model F's without the coordinates?

Presumably a map - internally, this is always what model amplitudes are calculated from anyway. -Nat

Pavel Afonine

2:23 p.m.

New subject: is there any phenix utility that can evaluate the Patterson Correlation function between exp and model data?

In theory one may have a non-atomic model, say a 3D function defining the molecular envelop or some other non-atomic representations (Kalinin, D. I. (1981). Kristallographiya, 25, 535-544.). Fourier transforming these objects will give you the model structure factors F. Pavel. On 6/20/11 9:53 AM, Jacob Keller wrote:

...

I am curious--how did you get model F's without the coordinates?

JPK

On Mon, Jun 20, 2011 at 9:52 AM, wrote:

...
Hi,

If I only have the experimental and model scattering factors (without model coordinates), is there any phenix utility that can evaluate the Patterson Correlation function between exp and model data?

By the way, is the one by FFT as described in (http://www.nature.com/nature/journal/v473/n7348/full/nature09964.html) implemented in Phenix?

Thanks a lot!

Hailiang

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zhangh1＠umbc.edu

3:02 p.m.

New subject: is there any phenix utility that can evaluate the Patterson Correlation function between exp and model data?

Yes, this is a coarse-grained model structure factor, and I want to refine it against Patterson correlation with the exp data. If there is no direct syntax, any suggestions about which module/file in the phenix package I should look for will be greatly appreciated! Best Regards, Hailiang

...

In theory one may have a non-atomic model, say a 3D function defining the molecular envelop or some other non-atomic representations (Kalinin, D. I. (1981). Kristallographiya, 25, 535-544.). Fourier transforming these objects will give you the model structure factors F.

Pavel.

On 6/20/11 9:53 AM, Jacob Keller wrote:

...
I am curious--how did you get model F's without the coordinates?

JPK

On Mon, Jun 20, 2011 at 9:52 AM, wrote:

...
Hi,

If I only have the experimental and model scattering factors (without model coordinates), is there any phenix utility that can evaluate the Patterson Correlation function between exp and model data?

By the way, is the one by FFT as described in (http://www.nature.com/nature/journal/v473/n7348/full/nature09964.html) implemented in Phenix?

Thanks a lot!

Hailiang

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Randy Read

21 Jun 21 Jun

4:45 a.m.

New subject: is there any phenix utility that can evaluate the Patterson Correlation function between exp and model data?

Is there a particular reason you want to use PC refinement? In most cases I think it is better to refine against a likelihood target. I think Frank used it in Rosetta for speed, which is more important when you have hundreds or thousands of trials. Regards, Randy Read On 20 Jun 2011, at 19:02, [email protected] wrote:

...

Yes, this is a coarse-grained model structure factor, and I want to refine it against Patterson correlation with the exp data.

If there is no direct syntax, any suggestions about which module/file in the phenix package I should look for will be greatly appreciated!

Best Regards, Hailiang

...
In theory one may have a non-atomic model, say a 3D function defining the molecular envelop or some other non-atomic representations (Kalinin, D. I. (1981). Kristallographiya, 25, 535-544.). Fourier transforming these objects will give you the model structure factors F.

Pavel.

On 6/20/11 9:53 AM, Jacob Keller wrote:

...
I am curious--how did you get model F's without the coordinates?

JPK

On Mon, Jun 20, 2011 at 9:52 AM, wrote:

...
Hi,

If I only have the experimental and model scattering factors (without model coordinates), is there any phenix utility that can evaluate the Patterson Correlation function between exp and model data?

By the way, is the one by FFT as described in (http://www.nature.com/nature/journal/v473/n7348/full/nature09964.html) implemented in Phenix?

Thanks a lot!

Hailiang

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------ Randy J. Read Department of Haematology, University of Cambridge Cambridge Institute for Medical Research Tel: + 44 1223 336500 Wellcome Trust/MRC Building Fax: + 44 1223 336827 Hills Road E-mail: [email protected] Cambridge CB2 0XY, U.K. www-structmed.cimr.cam.ac.uk

zhangh1＠umbc.edu

6 Jul 6 Jul

5:38 p.m.

New subject: calculate Fc for the whole unit cell from a Fc of a single symmetric unit.

Hi, I am wondering if I only have structure factors calculated from a single symmetric unit, is there any phenix utility which can calculate the structure factor for the whole unit cell given the symmetric operation or space group and crystal parameters? Note I don't have an atomic model and only have Fc. Thanks! Hailiang

Ralf Grosse-Kunstleve

8 Jul 8 Jul

6:44 p.m.

New subject: calculate Fc for the whole unit cell from a Fc of a single symmetric unit.

Did you get responses already? If not, could you explain your situation some more? We have algorithms that do the symmetry summation in reciprocal space. The input is a list of Fc in P1, based on the unit cell of the crystal. Is that what you have? Ralf On Wed, Jul 6, 2011 at 1:38 PM, wrote:

...

Hi,

I am wondering if I only have structure factors calculated from a single symmetric unit, is there any phenix utility which can calculate the structure factor for the whole unit cell given the symmetric operation or space group and crystal parameters? Note I don't have an atomic model and only have Fc.

Thanks!

Hailiang

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Ed Pozharski

10 Jul 10 Jul

1:18 p.m.

New subject: calculate Fc for the whole unit cell from a Fc of a single symmetric unit.

I suspect what Hailang means is expansion into P1. I am sure this can be accomplished through some either existing or easily coded cctbx tool. However, when I looked into a different task recently that included P1 expansion as a step, I learned that SFTOOLs can do this, albeit there was a bug there which caused trouble in certain space groups (may be fixed by now so check if there is an update). Hailang - if P1 expansion is what you need, I could share my own code as well, let me know if that is something you want to try. Cheers, Ed. On Fri, 2011-07-08 at 14:44 -0700, Ralf Grosse-Kunstleve wrote:

...

Did you get responses already? If not, could you explain your situation some more? We have algorithms that do the symmetry summation in reciprocal space. The input is a list of Fc in P1, based on the unit cell of the crystal. Is that what you have? Ralf

On Wed, Jul 6, 2011 at 1:38 PM, wrote: Hi,

I am wondering if I only have structure factors calculated from a single symmetric unit, is there any phenix utility which can calculate the structure factor for the whole unit cell given the symmetric operation or space group and crystal parameters? Note I don't have an atomic model and only have Fc.

Thanks!

Hailiang

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zhangh1＠umbc.edu

11 Jul 11 Jul

2:56 p.m.

New subject: calculate Fc for the whole unit cell from a Fc of a single symmetric unit.

Sorry I haven't got a chance to check my email recently. Yes, I meant expansion to P1. The thing is cctbx relies on the atomic model I think, but I only have model Fc available. Hailiang

...

I suspect what Hailang means is expansion into P1.

I am sure this can be accomplished through some either existing or easily coded cctbx tool. However, when I looked into a different task recently that included P1 expansion as a step, I learned that SFTOOLs can do this, albeit there was a bug there which caused trouble in certain space groups (may be fixed by now so check if there is an update).

Hailang - if P1 expansion is what you need, I could share my own code as well, let me know if that is something you want to try.

Cheers,

Ed.

On Fri, 2011-07-08 at 14:44 -0700, Ralf Grosse-Kunstleve wrote:

...
Did you get responses already? If not, could you explain your situation some more? We have algorithms that do the symmetry summation in reciprocal space. The input is a list of Fc in P1, based on the unit cell of the crystal. Is that what you have? Ralf

On Wed, Jul 6, 2011 at 1:38 PM, wrote: Hi,

I am wondering if I only have structure factors calculated from a single symmetric unit, is there any phenix utility which can calculate the structure factor for the whole unit cell given the symmetric operation or space group and crystal parameters? Note I don't have an atomic model and only have Fc.

Thanks!

Hailiang

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Ed Pozharski

3:34 p.m.

New subject: calculate Fc for the whole unit cell from a Fc of a single symmetric unit.

On Mon, 2011-07-11 at 13:56 -0400, [email protected] wrote:

...

but I only have model Fc available

You don't need a model to expand to P1. All you need is the symmetry operators. If you want to comb through cctbx code or other (e.g. I gleaned a lot of this stuff from clipper libs), the expansion is routinely done upon map calculation. I do have some code that may help you, albeit it may need to be modified a bit depending on your specifics (warning: it's all python). I've done some of this looking to calculate the electron density curvature, and the first step is to expand to P1 before you can do fourier transforms and such. Cheers, Ed -- "I'd jump in myself, if I weren't so good at whistling." Julian, King of Lemurs

Ralf Grosse-Kunstleve

4:42 p.m.

New subject: calculate Fc for the whole unit cell from a Fc of a single symmetric unit.

We can expand reciprocal-space arrays, too, with the cctbx.miller.array.expand_to_p1() method. You can use it from the command line via phenix.reflection_file_converter --expand-to-p1 ... See also: http://www.phenix-online.org/documentation/reflection_file_tools.htm Ralf On Mon, Jul 11, 2011 at 10:56 AM, wrote:

...

Sorry I haven't got a chance to check my email recently.

Yes, I meant expansion to P1. The thing is cctbx relies on the atomic model I think, but I only have model Fc available.

Hailiang

...
I suspect what Hailang means is expansion into P1.

I am sure this can be accomplished through some either existing or easily coded cctbx tool. However, when I looked into a different task recently that included P1 expansion as a step, I learned that SFTOOLs can do this, albeit there was a bug there which caused trouble in certain space groups (may be fixed by now so check if there is an update).

Hailang - if P1 expansion is what you need, I could share my own code as well, let me know if that is something you want to try.

Cheers,

Ed.

On Fri, 2011-07-08 at 14:44 -0700, Ralf Grosse-Kunstleve wrote:

...
Did you get responses already? If not, could you explain your situation some more? We have algorithms that do the symmetry summation in reciprocal space. The input is a list of Fc in P1, based on the unit cell of the crystal. Is that what you have? Ralf

On Wed, Jul 6, 2011 at 1:38 PM, wrote: Hi,

I am wondering if I only have structure factors calculated from a single symmetric unit, is there any phenix utility which can calculate the structure factor for the whole unit cell given the symmetric operation or space group and crystal parameters? Note I don't have an atomic model and only have Fc.

Thanks!

Hailiang

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_______________________________________________ phenixbb mailing list [email protected] http://phenix-online.org/mailman/listinfo/phenixbb

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zhangh1＠umbc.edu

7:01 p.m.

New subject: calculate Fc for the whole unit cell from a Fc of a single symmetric unit.

Thanks a lot!

...

We can expand reciprocal-space arrays, too, with the cctbx.miller.array.expand_to_p1() method. You can use it from the command line via

phenix.reflection_file_converter --expand-to-p1 ...

See also: http://www.phenix-online.org/documentation/reflection_file_tools.htm

Ralf

On Mon, Jul 11, 2011 at 10:56 AM, wrote:

...
Sorry I haven't got a chance to check my email recently.

Yes, I meant expansion to P1. The thing is cctbx relies on the atomic model I think, but I only have model Fc available.

Hailiang

...
I suspect what Hailang means is expansion into P1.

I am sure this can be accomplished through some either existing or easily coded cctbx tool. However, when I looked into a different task recently that included P1 expansion as a step, I learned that SFTOOLs can do this, albeit there was a bug there which caused trouble in certain space groups (may be fixed by now so check if there is an update).

Hailang - if P1 expansion is what you need, I could share my own code as well, let me know if that is something you want to try.

Cheers,

Ed.

On Fri, 2011-07-08 at 14:44 -0700, Ralf Grosse-Kunstleve wrote:

...
Did you get responses already? If not, could you explain your situation some more? We have algorithms that do the symmetry summation in reciprocal space. The input is a list of Fc in P1, based on the unit cell of the crystal. Is that what you have? Ralf

On Wed, Jul 6, 2011 at 1:38 PM, wrote: Hi,

I am wondering if I only have structure factors calculated from a single symmetric unit, is there any phenix utility which can calculate the structure factor for the whole unit cell given the symmetric operation or space group and crystal parameters? Note I don't have an atomic model and only have Fc.

Thanks!

Hailiang

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Edward A. Berry

7:35 p.m.

New subject: calculate Fc for the whole unit cell from a Fc of a single symmetric unit.

It seems to me there are two things that could be meant by "expand to P1" One is when data has been reduced to the Reciprocal Space asymmetric unit (or otherwise one asymmetric unit of a symmetric dataset has been obtained) and you want to expand it to P1 by using symmetry to generate all the symmetry -equivalent reflections. The other is where a full P1 dataset has been calculated from just one asymmetric unit of the crystal (and hence does not exhibit the crystallographic symmetry) and you want to generate the transform of the entire crystal. (I think this is how all the space-group - specific fft programs used to work before computers got so fast it was less bother to just do everything in P1 with the whole cell) Presumably this involves applying the real space symmetry operators to get n rotated (or phase-shifted for translational symmetry) P1 datasets and adding them vectorially. It would be important to decide which of these is required, and which each of the suggested methods provides eab Ralf Grosse-Kunstleve wrote:

...

We can expand reciprocal-space arrays, too, with the cctbx.miller.array.expand_to_p1() method. You can use it from the command line via

phenix.reflection_file_converter --expand-to-p1 ...

See also: http://www.phenix-online.org/documentation/reflection_file_tools.htm

Ralf

On Mon, Jul 11, 2011 at 10:56 AM, mailto:[email protected]> wrote:

Sorry I haven't got a chance to check my email recently.

Yes, I meant expansion to P1. The thing is cctbx relies on the atomic model I think, but I only have model Fc available.

Hailiang

> I suspect what Hailang means is expansion into P1. > > I am sure this can be accomplished through some either existing or > easily coded cctbx tool. However, when I looked into a different task > recently that included P1 expansion as a step, I learned that SFTOOLs > can do this, albeit there was a bug there which caused trouble in > certain space groups (may be fixed by now so check if there is an > update). > > Hailang - if P1 expansion is what you need, I could share my own code as > well, let me know if that is something you want to try. > > Cheers, > > Ed. > > On Fri, 2011-07-08 at 14:44 -0700, Ralf Grosse-Kunstleve wrote: >> Did you get responses already? >> If not, could you explain your situation some more? >> We have algorithms that do the symmetry summation in reciprocal space. >> The input is a list of Fc in P1, based on the unit cell of the >> crystal. Is that what you have? >> Ralf >> >> On Wed, Jul 6, 2011 at 1:38 PM, mailto:[email protected]> wrote: >> Hi, >> >> I am wondering if I only have structure factors calculated >> from a single >> symmetric unit, is there any phenix utility which can >> calculate the >> structure factor for the whole unit cell given the symmetric >> operation or >> space group and crystal parameters? Note I don't have an >> atomic model and >> only have Fc. >> >> Thanks! >> >> Hailiang >> >> _______________________________________________ >> phenixbb mailing list >> [email protected] mailto:[email protected] >> http://phenix-online.org/mailman/listinfo/phenixbb >> >> >> _______________________________________________ >> phenixbb mailing list >> [email protected] mailto:[email protected] >> http://phenix-online.org/mailman/listinfo/phenixbb > > > _______________________________________________ > phenixbb mailing list > [email protected] mailto:[email protected] > http://phenix-online.org/mailman/listinfo/phenixbb > >

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Dale Tronrud

8 p.m.

New subject: calculate Fc for the whole unit cell from a Fc of a single symmetric unit.

On 07/11/11 15:35, Edward A. Berry wrote:

...

It seems to me there are two things that could be meant by "expand to P1"

One is when data has been reduced to the Reciprocal Space asymmetric unit (or otherwise one asymmetric unit of a symmetric dataset has been obtained) and you want to expand it to P1 by using symmetry to generate all the symmetry -equivalent reflections.

The other is where a full P1 dataset has been calculated from just one asymmetric unit of the crystal (and hence does not exhibit the crystallographic symmetry) and you want to generate the transform of the entire crystal. (I think this is how all the space-group - specific fft programs used to work before computers got so fast it was less bother to just do everything in P1 with the whole cell) Presumably this involves applying the real space symmetry operators to get n rotated (or phase-shifted for translational symmetry) P1 datasets and adding them vectorially.

If I recall, that is how XPLOR calculated structure factors but that is not how a Ten Eyck space group specific FFT works. First it expands the atoms into the largest subgroup composed only of symmetry elements that can be optimized (e.g. three-folds are out). Then the electron density of the asymmetric unit of that space group is calculated. Finally the structure factors are calculated by a combination of line group optimized 1-D FFTs and clever rearrangements that move data from useless positions in memory to places where the final 1-D FFTs can use them. Both the calculation of the map (the slowest step) and the FFT itself are sped up by a factor of the number of usable symmetry operators. In addition the amount of RAM required was greatly reduced. Back in the day the latter was often more important because memory was so limited. Dale Tronrud

...

It would be important to decide which of these is required, and which each of the suggested methods provides

eab

Ralf Grosse-Kunstleve wrote:

...
We can expand reciprocal-space arrays, too, with the cctbx.miller.array.expand_to_p1() method. You can use it from the command line via

phenix.reflection_file_converter --expand-to-p1 ...

See also: http://www.phenix-online.org/documentation/reflection_file_tools.htm

Ralf

On Mon, Jul 11, 2011 at 10:56 AM, mailto:[email protected]> wrote:

Sorry I haven't got a chance to check my email recently.

Yes, I meant expansion to P1. The thing is cctbx relies on the atomic model I think, but I only have model Fc available.

Hailiang

> I suspect what Hailang means is expansion into P1. > > I am sure this can be accomplished through some either existing or > easily coded cctbx tool. However, when I looked into a different task > recently that included P1 expansion as a step, I learned that SFTOOLs > can do this, albeit there was a bug there which caused trouble in > certain space groups (may be fixed by now so check if there is an > update). > > Hailang - if P1 expansion is what you need, I could share my own code as > well, let me know if that is something you want to try. > > Cheers, > > Ed. > > On Fri, 2011-07-08 at 14:44 -0700, Ralf Grosse-Kunstleve wrote: >> Did you get responses already? >> If not, could you explain your situation some more? >> We have algorithms that do the symmetry summation in reciprocal space. >> The input is a list of Fc in P1, based on the unit cell of the >> crystal. Is that what you have? >> Ralf >> >> On Wed, Jul 6, 2011 at 1:38 PM, mailto:[email protected]> wrote: >> Hi, >> >> I am wondering if I only have structure factors calculated >> from a single >> symmetric unit, is there any phenix utility which can >> calculate the >> structure factor for the whole unit cell given the symmetric >> operation or >> space group and crystal parameters? Note I don't have an >> atomic model and >> only have Fc. >> >> Thanks! >> >> Hailiang >> >> _______________________________________________ >> phenixbb mailing list >> [email protected] mailto:[email protected] >> http://phenix-online.org/mailman/listinfo/phenixbb >> >> >> _______________________________________________ >> phenixbb mailing list >> [email protected] mailto:[email protected] >> http://phenix-online.org/mailman/listinfo/phenixbb > > > _______________________________________________ > phenixbb mailing list > [email protected] mailto:[email protected] > http://phenix-online.org/mailman/listinfo/phenixbb > >

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Ralf Grosse-Kunstleve

8:21 p.m.

New subject: calculate Fc for the whole unit cell from a Fc of a single symmetric unit.

Hi Ed, On Mon, Jul 11, 2011 at 3:35 PM, Edward A. Berry wrote:

...

It seems to me there are two things that could be meant by "expand to P1"

One is when data has been reduced to the Reciprocal Space asymmetric unit (or otherwise one asymmetric unit of a symmetric dataset has been obtained) and you want to expand it to P1 by using symmetry to generate all the symmetry -equivalent reflections.

This is what the cctbx.miller.array.expand_to_p1() method does. -- It is a very simple algorithm once you have the list of symmetry operations.

...

The other is where a full P1 dataset has been calculated from just one asymmetric unit of the crystal (and hence does not exhibit the crystallographic symmetry) and you want to generate the transform of the entire crystal. (I think this is how all the space-group - specific fft programs used to work before computers got so fast it was less bother to just do everything in P1 with the whole cell) Presumably this involves applying the real space symmetry operators to get n rotated (or phase-shifted for translational symmetry) P1 datasets and adding them vectorially.

I tend to call this "symmetry summation in reciprocal space". You are correct, this is used when we compute structure factors with the FFT method. Ralf

Ralf Grosse-Kunstleve

20 Jun 20 Jun

4:29 p.m.

New subject: is there any phenix utility that can evaluate the Patterson Correlation function between exp and model data?

Hi Hailiang,

...

If I only have the experimental and model scattering factors (without model coordinates), is there any phenix utility that can evaluate the Patterson Correlation function between exp and model data?

It is just the standard linear correlation coefficient (using i_obs and i_model for x and y), which is very easy to calculate. In another email you wrote that you want to do refinement. What are your variables?

...

By the way, is the one by FFT as described in (http://www.nature.com/nature/journal/v473/n7348/full/nature09964.html) implemented in Phenix?

http://www.phenix-online.org/documentation/mr_rosetta.htm Ralf

Nathaniel Echols

4:34 p.m.

New subject: is there any phenix utility that can evaluate the Patterson Correlation function between exp and model data?

On Mon, Jun 20, 2011 at 12:29 PM, Ralf Grosse-Kunstleve wrote:

...

...
By the way, is the one by FFT as described in (http://www.nature.com/nature/journal/v473/n7348/full/nature09964.html) implemented in Phenix?

http://www.phenix-online.org/documentation/mr_rosetta.htm

This doesn't actually say anything about the Patterson correlation. I'm pretty sure that Rosetta does that part, since the source code has some files that appear relevant. (But it's much easier to use CCTBX for this, once you know where to look.) -Nat

Thomas C. Terwilliger

4:36 p.m.

New subject: is there any phenix utility that can evaluate the Patterson Correlation function between exp and model data?

Hi Hailiang, No the patterson refinement in the mr-rosetta paper is not implemented in Phenix. Frank DiMaio in David Baker's lab wrote that as part of Rosetta. All the best, Tom T

...

...
Hi,

If I only have the experimental and model scattering factors (without model coordinates), is there any phenix utility that can evaluate the Patterson Correlation function between exp and model data?

By the way, is the one by FFT as described in (http://www.nature.com/nature/journal/v473/n7348/full/nature09964.html) implemented in Phenix?

Thanks a lot!

Hailiang

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