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PW91 Perdew-Wang generalized-gradient approximation Perdew and Wang (1992) BP Becke exchange plus Perdew correlation Becke (1988), Perdew and Wang (1992) PBE Perdew-Burke-Ernzerhof correlation Perdew et al. (1996) RPBE Revised PBE functional by Hammer et al. Hammer et al. (1999)

HCTH Hamprecht, Cohen, Tozer and Handy functional Boese and Handy (2001)

BLYP Becke exchange plus Lee-Yang-Parr correlation Becke (1988), Lee et al. (1988) BOP Becke One Parameter functional Tsuneda et al. (1999)

VWN-BP BP functional with the local correlation replaced by the VWN functional. Vosko et al. (1980), Becke (1988), Perdew and Wang (1992)

VWN: The Vosko-Wilk-Nusair (VWN) functional is the most popular LSD correlation potential. It uses a fit to accurate numerical results (by Ceperly and Alder) of a uniform electron gas. Ceperley and Alder performed quantum Monte Carlo calculations on a uniform electron gas at low and high spin limits for several electron densities. VWN uses the Pade interpolation procedure to fit the CA results for both the para and ferro states and for low and high densities. DMol3 uses the best VWN (so called \

PWC: The Perdew-Wang (PWC) functional is a recent parameterization of the Ceperley and Alder data, which corrects some VWN problems with fitting. PWC is the default functional for DMol3 calculations.

The local spin-density (LSD) approximation accurately predicts structures, vibrations, and relative energies of covalent systems; however, bond energies are seriously overestimated. The local DFT should not be used for systems with weak bonds, such as hydrogen bonds. These problems with the LSD method can be corrected to a large extent by using the so-called gradient-corrected (or nonlocal) functionals.

P91, BP, BLYP, BOP: DMol3 supports several nonlocal exchange and correlation functionals. The most popular, the Becke exchange functional (B88) is used in conjunction with the Perdew-Wang correlation functional (BP) or the Lee-Yang-Parr correlation functional (BLYP). The so-called generalized gradient corrected (GGA) functional, by Perdew and Wang (P91) was derived by considering low and high density regimes and by enforcing various summation rules.

PBE: The PBE (Perdew, Burke and Enzerhof) functional (1996, 1997) is another GGA functional in which all the parameters (other then those in its LDA component) are fundamental constants. The exchange part of this functional is similar to the Becke formula (1986), and the correlation part is close to the Perdew-Wang functional (1986).This functional has a strong physical background, reliable numerical performance and it is frequently used in DFT calculations.

RPBE: More recently, Hammer, Hansen and Norskov (1999) proposed a modified version of the PBE formula that improves considerably thermochemical results. So far this functional, called RPBE, has been mainly used for solids.

HCTH: The HCTH functional, named for the authors' initials (Hamprecht et al., 1998), represents a \DFT functional. Assuming that the exact functional will never be found, they propose a flexible form of gradient corrected functional that is fitted to the training set of molecules. The default for the current implementation, the so called HCTH/407 functional, that was obtained by fitting to the set of the 407 atomic and molecular systems (Boese and Handy, 2001). This functional was found to predict a much improved thermochemistry for inorganic and hydrogen bonded systems. The standalone keyword for this functional is hcth407. The original HCTH-type functionals can be activated by keyword hcth93 (Hamprecht et al, 1998) and hcth147 (Boese et al. 2000).

Although the NLSD methods are significantly better than the LSD method, particularly in studying chemical reactions, the NLSD methods may still lead to reaction barriers that are too low.

VWN-BP: The VWN-BP functional is recommended for COSMO and COSMO-RS studies.

Materials-Studio 论坛问答全集（精选众多论坛讨论贴）

1、问：用MS构造晶体时要先确立空间群,可是那些空间群的代码是啥意思啊,看不懂,我想做的是聚乙烯醇的晶体,嘿嘿,也不知道去哪 可以查到它的空间群

答：A、要做晶体，首先要查询晶体数据，然后利用晶体数据再建立模型。晶体数据来源主要是文献，或者一些数据库，比如CCDC。

你都不知道这个晶体是怎么样的，怎么指定空间群呢？要反过来做事情哦：）

B、我不知道你指示的代码是数字代码还是字母代码,数字代码它对应了字母的代码，而字母的代码它含盖了一些群论的知识(晶系,对

称操作等),如果要具体了解你的物质或者材料属于那一个群，你可以查阅一下相关的手册,当然你要了解一些基本的群论知识.MS自带 了一些材料的晶体结构,你可以查询一下.

2、问：各位高手，我用ms中的castep进行运算。无论cpu是几个核心，它只有一个核心在工作。这个怎么解决呢？ 答：请先确认以下几个问题：

1，在什么系统下装，是否装了并行版本。 2，计算时设置参数的地方是否选择了并行。 3，程序运算时，并不是时时刻刻都要用到多个CPU

3、问：我已经成功地安装了MS3.1的Linux版本， 串行的DMol3可以成功运行。

但是运行并行的时候出错。

机器是双Xeon5320(四核)服务器，rsh和rlogin均开启，RHEL4.6系统。 其中hosts.equiv的内容如下： localhost

ibm-console

machines.LINUX的内容如下： localhost:8

现在运行RunDMol3.sh时，脚本停在

$MS_INSTALL_ROOT/MPICH/bin/mpirun

$nolocal

-np

$nproc

$MS_INSTALL_ROOT/DMol3/bin/dmol3_mpi.exe $rootname $DMOL3_DATA

这一处，没法执行这一命令

并行运算时，出现以下PIxxxx(x为数字)输出

ibm-console 0 /home/www/MSI/MS3.1/DMol3/bin/dmol3_mpi.exe localhost 3 /home/www/MSI/MS3.1/DMol3/bin/dmol3_mpi.exe 请问这是什么原因？谢谢！

答：主要是rsh中到ibm-console的没有设置 把/etc/hosts改为

127.0.0.1 localhost.localdomain localhost ibm-console 在后面加个ibm-console 也希望对大家有帮助!

4、问：在最后结果的dos图中,会显示不同电子spd的贡献,我想问的是,

假设MS考虑的原子Mg的电子组态为2p6 3s2,那么最后的dos结果中的s,p是不是就是2p,跟3s的贡献.比如更高能量的3p是否可能出现在

dos中?

如果可能的话，在这种情况下,如何区分2p和3p的贡献,谢谢. 答：A、取决于你的餍势