Why is it not converged at low temperatures in SCPH?

[gangliu-github]

I performed the SCPH calculation. It is not converged at low temperatures (0K, 100K, 200K), while it achieved convergence at high temperatures (300~1200K).
Why? How can I improve the convergence of SCPH?

[ttadano]

A potential solution is to use a smaller MIXALPHA and a smaller DT.

[gangliu-github]

Thanks! I will try.

[gangliu-github]

I have tried the solution, and it improved the convergence really! Thank you!