Gaussian: Relaxed scan with modredundant optimization and dummy atoms
I would like to perform a relaxed scan in Gaussian09 on my molecule using the modredundant optimization. Because I want to scan over two bond lengths simultaneously, I defined some dummy atoms which are close to the real atoms whose bond lenghts should be scanned. However, this approach does not work, because I can't properly index the dummy atoms. 724
The Gaussian09 documentation says (emphasis mine):
[Type] N1 [N2 [N3 [N4]]] S nsteps stepsize [[min] max]]
N1, N2, N3 and N4 are atom numbers or wildcards (discussed below). Atom numbering begins at 1, and any dummy atoms are not counted.
How can I then perform a scan referencing a dummy atom? I don't want to do the scan using the z-matrix optimization because it does not converge.
Here is my input file:
%nprocshared=16
%mem=5gb
%chk=4MeAminoButanal
#P HF/6-31G(d) opt=(modredundant) scrf=(pcm) nosymm
4MeAminoButanal dummy scan
0 1
C 0.000000 0.000000 0.000000
N 0.000000 0.000000 1.451901
C 1.325038 0.000000 2.055476
C 1.991320 1.<PHONE_NUMBER> 2.032970
C 1.229182 2.449098 2.809397
C 1.309917 2.335179 4.306919
X -<PHONE_NUMBER> -<PHONE_NUMBER> 1.611583
X -1.041414 -0.131882 1.066579
H 1.218960 -0.323776 3.083767
H 1.990264 -<PHONE_NUMBER> 1.564774
H 2.993872 1.281489 2.436811
H 2.106328 1.711600 1.006802
H 1.602469 3.443240 2.566292
H 0.178120 2.455789 2.536445
H <PHONE_NUMBER> 3.065770 4.854632
H -1.016528 -0.113770 -<PHONE_NUMBER>
H <PHONE_NUMBER> <PHONE_NUMBER> -0.379032
H <PHONE_NUMBER> -0.798850 -<PHONE_NUMBER>
X <PHONE_NUMBER> 1.939406 4.607116
X 1.311963 2.318294 5.471711
O 1.974063 1.543637 4.907309
H -<PHONE_NUMBER> -<PHONE_NUMBER> 1.771266
B 7 19 S 60 -0.05
B 22 7 F
B 2 7 F
B 6 19 F
B 21 19 F
When I run it, Gaussian09 obviously complains with
The following ModRedundant input section has been read: Invalid atom number. B 7 19 S 60 -0.05 268