Gaussian (v.03, 09, 16) is a popular computational chemistry software for quantum chemical calculations. Despite its many benefits, users may encounter various error messages, which can be caused by a variety of factors, including input errors, convergence issues, or hardware/software limitations. Resolving these error messages is essential for obtaining accurate results, identifying and correcting input mistakes, and advancing research in the field of computational chemistry. Below, we have summarized some frequently encountered error messages in Gaussian 16 and their corresponding solutions, which can assist users in troubleshooting issues and improving the accuracy of their calculations.
1. Errors caused by inappropriate coordinate system or geometry
UFF calculation of energy and first derivatives. Linear angle in Tors. Error termination via Lnk1e in /act/apps/Gaussian16a03/g16/l402.exe at Wed Feb 23 12:26:20 2022.
#p uff opt=cartesian scrf=(solvent=water,pcm) 0 1 O 25.11500000 22.43110000 6.97120000 O 22.62080000 23.04530000 7.53600000 O 25.11500000 26.81350000 6.97030000 O 34.24260000 32.69830000 6.97120000 O 31.74900000 33.31250000 7.53600000
Solution and Discussions:
The first thing we should try first is to set "OPT=Cartesian", which can force Gaussian to use cartesian coordinates rather than inner coordinates. However, this doesn't work for our case. After double-checking all the keywords, we take a closer look at the coordinate parameters and found that the significant digits of these parameters are too few. This can make the structure too "symmetric", and thus mislead Gaussian to determine that some bond angles are 180 degrees. An easy solution is to add a very small random number to each coordinate parameter to break the symmetry, which can be done with Excel or a few lines of python/shell codes：
0 1 O 25.11515690 22.43141230 6.971275674 O 22.62149746 23.04565043 7.536346204 O 25.11577049 26.81375715 6.971277549 O 34.24268655 32.69893546 6.972127916 O 31.74915798 33.31334506 7.536653410
WIth the new coordinate parameters, the job can run properly.
2. Errors caused by inappropriate basis-set settings
IBasis= 50 is unrecognized in AtmBas
#p genecp empiricaldispersion=gd3 scrf=(solvent=water,pcm) b3lyp 6-31+G** Zn-OH -1 1 O 0.000000000 0.000000000 0.1074550000 H 0.000000000 0.000000000 -0.859638000
Solution: Remove genecp. Only one basis set is used here.
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