# CCL:G: Units in Transition Dipole Matrix of Gaussian Anharmonic Calculation

• From: "Robert William Molt" <r.molt.chemical.physics]*[gmail.com>
• Subject: CCL:G: Units in Transition Dipole Matrix of Gaussian Anharmonic Calculation
• Date: Thu, 13 Apr 2017 07:24:25 -0400

``` Sent to CCL by: "Robert William Molt"
[r.molt.chemical.physics|,|gmail.com]
I have a question pertaining to the units in the output of a Gaussian09 revision
E
calculation. I have tried contacting the folks at Gaussian, but they elected not
to
respond. I am hoping someone has experience to know the unit choice.
In an anharmonic calculation (i.e., specified by #p B971/gen freq=
(anharmonic,readanharm)), in the output, one can find the anharmonic transition
moments. What are the units? Are they in Bohr radii or in Angstroms? Unless the
table is
referring to the derivative of the electric dipole moment with respect to the
normal mode
and thus unitless? The table in question is printed below, as a example. I
certainly hope
the answer isn't obvious and I am just missing it!
==================================================
Anharmonic Transition Moments
==================================================
Electric dipole : Fundamental Bands
------------------------------------------------------------------------
Mode(Quanta)             X                 Y                 Z
1(1)               -0.229363E-02      0.216347E-04 -0.165372E-04
2(1)               -0.378456E-05     -0.757900E-02 0.495758E-02
3(1)               -0.174538E-03     -0.292937E-01 -0.108572E-01
4(1)                0.640748E-02     -0.147416E-03 -0.387546E-04
5(1)               -0.331733E-03     -0.412749E-02 0.217199E-01
6(1)               -0.322556E-01      0.140901E-03 -0.301806E-03
7(1)               -0.135410E-04      0.157547E-01 -0.349931E-01
8(1)                0.339716E-01     -0.840677E-04 -0.669247E-04
9(1)                0.106962E-03      0.291647E-01 -0.150517E-01
10(1)                0.835677E-04      0.188475E-01 0.131796E-01
11(1)                0.623295E-02     -0.124958E-03 -0.688922E-04
12(1)                0.250309E-05      0.635861E-03 0.153666E-01
13(1)               -0.165867E-01      0.545289E-04 0.397994E-05
14(1)                0.363989E-04      0.402722E-02 -0.120758E-01
15(1)               -0.410448E-02      0.317111E-04 -0.106966E-04
16(1)                0.116963E-01     -0.440165E-04 0.532907E-05
17(1)                0.118271E-05      0.652388E-03 -0.173159E-02
18(1)                0.351650E-04      0.977472E-02 -0.934390E-02
19(1)               -0.234592E-01      0.717347E-04 -0.519995E-05
20(1)                0.836829E-04      0.252747E-01 0.380139E-01
21(1)               -0.806775E-02      0.324950E-04 0.131289E-04
22(1)                0.279633E-01     -0.109396E-03 0.593255E-05
23(1)                0.203583E-04      0.792405E-02 0.338931E-01
24(1)                0.481287E-04      0.162253E-01 -0.243383E-01
25(1)                0.612414E-04      0.203126E-01 0.409559E-01
26(1)               -0.101900E-01      0.478852E-04 0.820998E-05
27(1)               -0.303762E-04     -0.882881E-02 -0.330163E-01
28(1)               -0.442498E-04     -0.440780E-03 -0.292694E-02
29(1)                0.157015E-01     -0.644128E-04 -0.351860E-05
30(1)                0.154980         -0.536615E-03 0.152241E-04
```