newton command

Syntax

newton flag
newton flag1 flag2

• flag = on or off for both pairwise and bonded interactions

• flag1 = on or off for pairwise interactions

• flag2 = on or off for bonded interactions

Examples

newton off
newton on off

Description

This command turns Newton’s 3rd law on or off for pairwise and bonded interactions. For most problems, setting Newton’s 3rd law to on means a modest savings in computation at the cost of two times more communication. Whether this is faster depends on problem size, force cutoff lengths, a machine’s compute/communication ratio, and how many processors are being used.

Setting the pairwise newton flag to off means that if two interacting atoms are on different processors, both processors compute their interaction and the resulting force information is not communicated.

Aspherix® should produce the same answers for any newton flag settings, except for round-off issues.

Restrictions

The newton bond setting cannot be changed after the simulation box is defined by a read_data or create_box command.

Some commands may not support newton “on”. You will see an error message in this case when running the simulation.

Default

newton on