ABINIT Discussion Forums

Hello

I am doing strain perturbation calculations on a compound which has some acoustic sum rule breaking. Anaddb complains in the following way

elast9 : WARNING - :
Acoustic sum rule violation met : the eigenvalues of accoustic mode
are too large at Gamma point
increase cutoff energy or k-points sampling.
The three eigenvalues are: 5.643424E-03 -1.004065E-03 3.614308E-03

Does this mean that elast9 can not use the enforced ASR correction? I also set asr 1 or 2 in the anaddb input, which usually corrects things for acoustic frequencies, but there is no change in the elastic calculation. Is there a fundamental reason this can not be used, or is it just not coded?

Cheers

Matthieu

Dear Matthieu,

I always had this warning when doing strain perturbation. So I cheked the code and I found that ASR is not coded in both elast9 and instr9.

best regards

Ilyes,

hello again,

The ASR correction has been added to 6.7.1 and will be available in abinit 6.8 shortly.

Matthieu