Master

See merge request !47

Master pre stage

See merge request !45

Master pre stage

See merge request !44

CUDA minor updates

See merge request !43

One index shift is moved from outside the kernel to inside the kernel.
Shouldn't really change anything. Just making the code more readable
and more consistent with the paper.

Reproducible code

See merge request !42

Reorganize files

See merge request !41

Threshold for check pd

See merge request !40

Now "thres_pd" can be set and used in single-precision calculations.

This is to make the check_pd feature more usable in electronic structure
theory software.

Use `#!/usr/bin/env python3`

See merge request !39