QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: Dipankar Saha on October 27, 2018, 14:18

Title: Total free energy
Post by: Dipankar Saha on October 27, 2018, 14:18

Hi,

How the 'Total free energy' is different from the 'Total energy (broadening->0)' ?

Thanks and Regards_
Dipankar

Title: Re: Total free energy
Post by: Petr Khomyakov on October 29, 2018, 10:24

The total energy is computed for a given broadening quantified with some artificial temperature when setting the calculator. Even so this is an artificial temperature introduced to speed up convergence of SCF, there is an entropy term -T*S in the corresponding free energy expression ('Total free energy' at T<> 0 K). The true ground state energy (i.e., at T=0 K) is given by  'Total energy (broadening->0)' .

Title: Re: Total free energy
Post by: Dipankar Saha on October 29, 2018, 10:56

Okay... I understand. Thank you!