Dynamical structure factor depended on Temperatrue

[tomoya1017]

Hello. I'd like to ask how to calculate the Dynamical structure factor depending on temperature with HPhi. I've already calculated it at 0 K. However, I don't make sense how to calculate Dynamical structure factor depended on Temperatrue.

[k-ido]

HPhi does not support functionality to directly calculate finite temperature spectra.
One possible way for such calculations is to perform the real-time evolution of typical states (for example, Phys. Rev. Lett. 90, 047203 (2003) and Phys. Rev. B 92, 205103 (2015)).
This approach also requires additional functionality to apply an excitation operator to typical states before real-time evolution,
but I believe it can be implemented by combining existing code already implemented in HPhi.

[tmisawa]

@tomoya1017
For your information, the output of typical states is now available in the develop branch.
For details, please refer to #153.

[tomoya1017]

Thank you. I checked #153 and implemented codes. But do I calculate the dynamical structure factor depended on temperature if I refer to #153?

[tmisawa]

I am sorry for the delayed reply.
As stated in #153 , the TPQ state can indeed be output and used as an input for real-time evolution.
However, to compute the dynamical Green’s function, you need to apply an operator to the time-evolved wavefunction. Doing so requires appropriate modifications to the code.
Therefore, please note that with the current features of HPhi alone, it is not possible to calculate the finite-temperature dynamical Green’s function.