Subject: Re: CCL:calculating NMR spectra for crystal structures

From: [email-masked]
Date: Tue, 4 Feb 2003 10:04:58 +0000

Dear Betty,

The state-of-the-art solid state NMR is implemented by Francesco
Mauri and Chris Pickard in Mauri's code PARATEC [this is currently
being incorporated in CASTEP]. I think Chris is in the best position
to tell you about the computational cost: [email-masked]

He would also explain why their approach is more complete and
accurate than the one in CPMD. Here is a brief list of current
publications from this group (PRB paper has the details of the 
implementation
and comparisons to quantum-chemistry formalisms as in Gaussian): 

http://ojps.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRLTAO000088000008086403000001&idtype=cvips&gifs=yes

First-principles theory of the EPR g tensor in solids: Defects in quartz
Pickard CJ, Mauri F
PHYSICAL REVIEW LETTERS 88 (8): art. no. 086403 FEB 25 2002

A theory for the reliable prediction of the EPR g tensor for paramagnetic 
defects in solids is presented. It is based on density functional theory 
and on the gauge including projector augmented wave approach to the 
calculation of all-electron magnetic response. The method is validated by 
comparison with existing quantum chemical and experimental data for a 
selection of diatomic radicals. We then perform the first prediction of 
EPR g tensors in the solid state and find the results to be in excellent 
agreement with experiment for the E-1' and substitutional phosphorus 
defect centers in quartz.

http://ojps.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRLTAO000087000008085506000001&idtype=cvips&gifs=yes

Atomic structure of icosahedral B4C boron carbide from a first principles 
analysis of NMR spectra
Mauri F, Vast N, Pickard CJ
PHYSICAL REVIEW LETTERS 87 (8): art. no. 085506 AUG 20 2001

Density functional theory is demonstrated to reproduce the C-13 and B-11 
NMR chemical shifts of icosahedral boron carbides with sufficient accuracy 
to extract previously unresolved structural information from experimental 
NMR spectra. B4C can be viewed as an arrangement of 3-atom linear chains 
and 12-atom icosahedra. According to our results, all the chains have a 
CBC structure. Most of the icosahedra have a B11C structure with the C 
atom placed in a polar site, and a few percent have a B-12 structure or a 
B10C2 structure with the two C atoms placed in two antipodal polar sites.

http://ojps.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRBMDO000063000024245101000001&idtype=cvips&gifs=yes

All-electron magnetic response with pseudopotentials: NMR chemical shifts
Pickard CJ, Mauri F
PHYSICAL REVIEW B 63 (24): art. no. 245101 JUN 15 2001

A theory for the ab initio calculation of all-electron NMR chemical shifts 
in insulators using pseudopotentials is presented. It is formulated for 
both finite and infinitely periodic systems and is based on an extension 
to the projector augmented-wave approach of Blochl [P. E. Blochl, Phys. 
Rev. B 50, 17 953 (1994)] and the method of Mauri et al. [F. Mauri, B. G. 
Pfrommer, and S. G. Louie, Phys. Rev. Lett. 77, 5300 (1996)]. The theory 
is successfully validated for molecules by comparison with a selection of 
quantum chemical results, and in periodic systems by comparison with 
plane-wave all-electron results for diamond.

http://www.iop.org/EJ/S/UNREG/ks17LhBicNsPpD6NufvXEA/abstract/0953-8984/14/11/310

Applications of ab initio atomistic simulations to biology
Segall MD
JOURNAL OF PHYSICS-CONDENSED MATTER 14 (11): 2957-2973 MAR 25 2002

Biological systems provide a particularly challenging set of problems for 
the application of ab initio quantum mechanical simulations. Despite this, 
these methods are providing insights into biological structures and 
processes at an atomistic level. 
This paper outlines current methods for first-principles modelling of 
biological systems. Example applications to the cytochrome P450 family of 
metabolic enzymes, photoreactive rhodopsin proteins and the calculation of 
NMR chemical shifts are described. Finally, trends in the development of 
new algorithms and the biological problems to which they will be applied 
are discussed.

=============================================================
Victor Milman             * Fellow
Accelrys Inc              * tel: (01223) 228500/228619
334 Science Park          * fax: (01223) 228501
Cambridge CB4 0WN         * tel. from abroad: +44 1223 228500
UK                        * e-mail: [email-masked]
=============================================================

"Coussens, Betty" <[email-masked]>
Sent by: "Computational Chemistry List" <[email-masked]>
03/02/2003 13:22

        To:     "[email-masked]'" <[email-masked]>
        cc: 
        Subject:        CCL:calculating NMR spectra for crystal structures

Dear all,

I would like to calculate NMR chemical shifts for a number of crystal
structures containing H, C, N, O and P atoms.  I know that this is 
possible
using e.g. plane wave codes like CPMD but I would like to hear the opinion
of you who have a lot of experience with this type of computations.  Can
anybody tell me what type of codes are most suitable for my purpose and 
give
me an idea about typical CPU timings for these type of calculations? 

Thanks a lot!

Betty 

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