Parameter: npart

Definition

Number of parts that the imaginary time axis is split.

Type

Integer

Default value

4

Component

Only for the BEGONIA, LAVENDER, MANJUSHAKA, and PANSY components.

Behavior

All operators in the imaginary time axis are grouped into npart parts according to their time values, in each Monte Carlo steps, only those changed parts are carefully dealt with, not all the parts. This trick can accelerate the codes significantly.

Comment

$2\sqrt{3 \langle k \rangle \text{nband}} \sim 4\sqrt{3 \langle k \rangle \text{nband}}$ may be the optimal value for npart to achieve maximum performance where $\langle k \rangle$ is the averaged perturbation expansion order. See nband for more details.