how to calculate frequency intensity in vasp

Message

landscy12 · #1 Post by **landscy12** » Fri Jun 09, 2006 10:06 am

I want to know whether vasp can calculate the frequency intensity in vasp? because I am going to plot the IR spectrum similar to the experiment, but I dont know how to get the intensity of every frequency. If you have such experience , can you tell me the answer? thanks very much.

landscy12 · #2 Post by **landscy12** » Fri Jun 09, 2006 12:39 pm

anyone?

bandy · #3 Post by **bandy** » Mon Jun 12, 2006 3:21 am

So far I know it can not do. But there are variables assigned for doing that task in the code.

landscy12 · #4 Post by **landscy12** » Thu Jun 15, 2006 2:32 am

hi, bandy, thank you. you mean that I should add something in the source code?

bandy · #5 Post by **bandy** » Tue Jun 20, 2006 2:03 am

Hi

Numerically there are two methods to calculate IR intensities:

1. from first derivatives of forces wrt electric field
2. from first derivatives of dipole moment wrt positions of ions

May be somebody can give us a complete algo.