Dear Prof. Baroni:
According to the linear response theory and 2n+1 theorem
(Rev.Mod.Phys.73,515),
it seems that PWSCF can not calculate 4-phonons interactions. But in effect,
the process of 4-phonons interactions is as important as 3-phonons
interactions.
Then my question is:
Is there any approach to calculate the anharmonicity of some vibration
modes including 4-phonons interactions ?
Thank you for your time to read my message!
Best Wishes!
Yours Sincerely
L.F.Huang
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L.F.Huang(???) lfhuang at theory.issp.ac.cn
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Add?Research Laboratory for Computational Materials Sciences,
Instutue of Solid State Physics,the Chinese Academy of Sciences,
P.O.Box 1129, Hefei 230031, P.R.China
Tel: 86-551-5591464-328(office)
Fax: 86-551-5591434
Web: http://theory.issp.ac.cn (website of our theory group)
http://www.issp.ac.cn (website of our institute)
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