高斯错误修改总结

I solved the problem using a variation on the first suggestion. Normally the scf took less than 80 cycles to converge. So i used scf=(Maxconventionalcycles=100,xqc) which resulted in a good compromise between using scf=qc and optimisation speed. In the case of the DIIS error the scf always took more than 100 cycles before the error, so by adding scf=(Maxconventionalcycles=100,xqc) the scf switched to qc after 100 cycles in the standard DIIS mode.

l9999错误是优化圈数不够，把out文件保存成gjf，修改后接着优化。这样比较省事。或者在原来输入文件opt中加入maxcyc=500,把优化圈数加大到500 L1002错误贋势基组不对，换基组，或者用guess=Indo L9999

Optimization stopped.

-- Wrong number of Negative eigenvalues: Desired= 1 Actual= 3 -- Flag reset to prevent archiving. 这是你原来贴的出错信息。

显然，gaussian检测了虚频个数，发现是3个而非1个——过渡态有且只有一个虚频，从而终止，显示出错。

加上noeigentest的意思是在优化过程中不必每步都去检测虚频个数，而是按照最可能的方式继续寻找下去，到跑完为止，所以如果你对过渡态的初始构型不是非常有把握的情况下，加上noeigen是比较不错的选择。

但你现在继续出状况，却没有贴新的出错信息，我没法猜这次是什么问题。。。 同时你那个命令行# b3lyp/6-31++g(d,p) opt=(ts,calcfc,noeigen) freq test 改成#p b3lyp/6-31++g(d,p) opt=(ts,calcfc,noeigen) freq

也就是任何时候#后面都要加一个p，结尾那个test不要写，被人笑话的。

Inaccurate quadrature in CalDSu 错误解决方法

已有 3175 次阅读 2012-7-4 16:27 |个人分类:Gaussian|系统分类:科研笔记

Inaccurate quadrature in CalDSu 错误解决方法

g09/g03 输出文件最后几行大致如下： Spurious integrated density or basis function:

NE= 149 NElCor= 0 El error=2.83D-03 rel=1.89D-05 Tolerance=1.00D-03 Shell 67 absolute error=2.30D-02 Tolerance=1.20D-02 Shell 67 signed error=2.30D-02 Tolerance=1.00D-01 Inaccurate quadrature in CalDSu.

Error termination via Lnk1e in /home/soft/g03/l502.exe at Mon Feb 23 09:42:55 2009. Job cpu time: 0 days 0 hours 0 minutes 3.1 seconds.

File lengths (MBytes): RWF= 13 Int= 0 D2E= 0 Chk= 13 Scr= 1

解决方法

1. 对某些分子，可以设置guess=indo。(Guess=indo的意思是：使用Gaussian98的默认初始猜测：对第一行元素是INDO，第二行元素是CNDO，第三行及以后的元素是Huckel。如果不写Guess=indo，则使用Gaussian03的默认初始猜测：全部使用Huckel初始猜测。Guess=indo的用处：使比较差的初始构型，能比较顺利地通过初始猜测。) 2. 对于对称分子，设置scf(dsymm) 强制使用密度对称。 3. 对于对称分子，设置全局nosymm，降低对称性。 4. 使用scf(novaracc)也可能会产生或消除这个错误。

5. 加上int(untrafine)，不过这个改变了积分网格，这个计算出的能量不能与同类计算直接比较。

6. 最佳解决方法：加关键词int(NoXCTest) 网格问题(G09默认的精度检测方法不适用,加上Int=NoXCTest), Skip tests of numerical accuracy of XC quadrature (g09手册)。需要检测结果波函数是否正确。可同时加guess=indo。

Error in internal coordinate system. 可在opt中加入cartesian 例如：

%chk=TS3-D-itm3-eoc-4.chk %mem=45000MB %NProcShared=8

#B3LYP/6-31G** iop(5/13=1) iop(2/11=1) #scf=(maxcycle=200)

#opt=(cartesian,TS,calcfc,noeigen,maxcycle=200) freq #geom=allcheck

Error in internal coordinates

created: 2009-07-31 14:38:48

This topic covers how to solve the \Error in internal coordinates\ problem.

Some times Gaussian quits at the Berny optimization stage with the \Error in internal coordinates\ message. This happens as Berny optimization by default uses redundant internal coordinates. Cartesian coords are easy to define and use but can be strongly coupled to one another. Interal coords describe molecular properties (bond lengths, angle...) naturally and thus involve less coupling. There are a few types of redundant internal coords which can accelerate opt process. But when a molecule has flat geometry, it

could be hard to calculate the reverse matrix of redundant internal coords. Therefore, it is better to switch back to Cartesian (opt=(...,Cartesian,...)) or use \nosymm\

GradGradGradGradGradGradGradGradGradGradGradGradGradGradGradGradGradGrad Berny optimization.

NTrRot= -1 NTRed= 29 NAtoms= 10 NSkip= 5 IsLin=F Error in internal coordinate system.

Error termination via Lnk1e in /home/cast/program/g09/l103.exe at Tue Nov 23 13:44:47 2010.

本人计算时出现如上错误，哪位达人知道是怎么回事？我觉得我的结构应该没问题 加上关键词OPT=Cartesian！