Standard scan range for improper/non-rotatable torsions

[jthorton]

ISSUE we have the ability to scan improper/ring-torsions now, but should we automatically apply some default limit on the scan range? or will torsiondrive cope with standard settings and stop grid points over a certain energy threshold?

TODO

• [X] Investigate submitting improper/ring-torsions under standard settings does this still work?
• [ ] Work out a suitable limit for the scan range for such torsions

[jchodera]

I'd be surprised if the standard settings worked, but it's worth a try! A limit in torsional displacement would be simple to implement, but if it was straightforward to develop, perturbations up to a limit in strain energy (above the minimum) would seem to be a more useful parameter to specify.

[davidlmobley]

I believe it stops grid points over a certain threshold, but that'd be a question for @leeping . I am fairly certain he has this in place though. Still, some default limit on the scan range may make sense.

@jmaat also may have insights as this has some similarity to things she was thinking about in her work on impropers. Or at least she may also know the answer.

[leeping]

TorsionDrive has the option to specify limited ranges of angles and an upper limit to the energy, but they don't come by default and you need to set them. I think this should be available through both the command line and API but @yudongqiu would know more details.

[jmaat]

From my work, I found that scanning from -50 to +50 degrees around the improper angle would typically capture the full minima. This the the range we used for the improper grid optimization datasets in QCA. I would suggest a limit from -60 to 60 for the improper angle based off of these results.

[jthorton]

Thanks for the advice it seems like Torsiondrive is naturally handling this problem with its energy cut off, I have found a few ring torsions in the archive already which appropriately limit the scan range of ring torsions even when the full scan range is requested. I have also introduced a way for users to specify a different scan range if they wish to limit them to the range @jmaat suggests though.