文档介绍：计算化学理论和应用 -第五讲
putational Chemistry laboratory
Beijing Normal university
BSSE效应算例
H2O二聚体相互作用能的计算
%chk=H2O-dimer-
#p hf/6-31g counterpoise=2
water dimer counterpoise
0 1
8 - 1
1 - - - 1
1 - - 1
8 - - 2
1 2
1 - - 2
Counterpoise: corrected energy = -
Counterpoise: BSSE energy =
%chk=H2O-dimer-
#p hf/6-31g massage
water dimer bsse
0 1
8 -
1 - - -
1 - -
8 - -
1
1 - -
1 NUC
2 NUC
3 NUC
%chk=H2O-dimer-
#p hf/6-31g massage
water dimer bsse
0 1
8 -
1 - - -
1 - -
8 - -
1
1 - -
4 NUC
5 NUC
6 NUC
G98
G03
Total
-
-
H2O 1
-
-
H2O 2
-
-
Interaction energy
-
-
自旋污染的解决办法
UHF计算得到的波函数不是<S2>本征函数
未成对电子数 S <S2>=S(S+1)
0 0 0
1
2 1
………………
污染大的计算方法:UHF UMP2 UMP3 UMP4
污染小的计算方法:LMP2 CI 计算基本上没有自旋污染问题
自旋投影算符法
Gaussian中包含有此方法:
Annihilation of the first spin contaminant:
S**2 before annihilation , after
另外,可以加IOP(5/14=2)选项来输出消除自旋污染后的电荷布居
Gaussian作业输出示例(H2O SP)
Entering Link 1 = C:\G03W\ PID= 1572.
Copyright (c) 1988,1990,1992,1993,1995,1998,2003, Gaussian, Inc.
All Rights Reserved.
This is the Gaussian(R) 03 program. It is based on the
the Gaussian(R) 98 system (copyright 1998, Gaussian, Inc.),
the Gaussian(R) 94 system (copyright 1995, Gaussian, Inc.),
the Gaussian 92(TM) system (copyright 1992, Gaussian, Inc.),
the Gaussian 90(TM) system (copyright 1990, Gaussian, I