[SOLVED] How to add Dipole

abid · 2015-12-14 22:47:30

want to place a dipole of given strength at some distance from linear molecule, Can you suggest how can I do this in molcas?
Linear molecule is for example CO and I want Dipole at distance of 1 angstroms from O atom.
Thanks

Ignacio · 2015-12-15 09:21:46

Look up the XFIEld keyword in gateway (http://www.molcas.org/documentation/man … 0000000000). You'd specify something like:

XField
1 Angstrom 1
1.20 3.40 5.60 0.0 0.1 0.2 0.3

Where a dipole with dipole moment (0.1,0.2,0.3) (atomic units, I guess), is placed at the point (1.20,3.40,5.60) Å.

abid · 2016-01-20 11:13:25

If I want to place two point charges at some particular point (with x,y,z coordinates), then I should proceed as follows
XField
2
0.0 0.0 2.0 1.0 0 0 0
0.0 0.0 2.7 -1.0 0 0 0
where first three are coordinates (x,y,z) 1 and -1 is charge along with 0 dipole.
Will this work for the purpose to study the dipole moment created by point charges?
Please give me your suggestions

Last edited by abid (2016-01-20 11:14:30)

niko · 2016-01-20 11:41:14

These two point charges create a dipole moment which can polarize the wavefunction of your system, hence its dipole moment. Alternatively you can place a similar (= same amplitude and direction, ie along the z axis) dipole moment at the center of charge of the two charges, ie coordinates 0.0 0.0 2.35.

abid · 2016-01-20 11:50:25

Dear niko, is it correct way to place the charges so that my wavefunctions get polarized under the effect of these point charges?

niko · 2016-01-20 15:48:42

abid wrote:

Dear niko, is it correct way to place the charges so that my wavefunctions get polarized under the effect of these point charges?

Yes, it is. The external potential (only nuclear charges normally) includes the contribution from the external point charges.

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#1 2015-12-14 22:47:30

[SOLVED] How to add Dipole

#2 2015-12-15 09:21:46

Re: [SOLVED] How to add Dipole

#3 2016-01-20 11:13:25

Re: [SOLVED] How to add Dipole

#4 2016-01-20 11:41:14

Re: [SOLVED] How to add Dipole

#5 2016-01-20 11:50:25

Re: [SOLVED] How to add Dipole

#6 2016-01-20 15:48:42

Re: [SOLVED] How to add Dipole

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