alchemical sterics exclude sigma

[Dan-Burns]

Is the sigma term of the lennard-jones potential affected when alchemically modifying sterics?

If so, I'd like the option to only apply it to epsilon. Can somebody point me to where I can make this edit? I'm assuming it's in alchemy.py but I can't figure out where.

Thank you, Dan

[zhang-ivy]

Is the sigma term of the lennard-jones potential affected when alchemically modifying sterics?

It looks like it is, see: https://github.com/choderalab/openmmtools/blob/main/openmmtools/alchemy.py#L1379-L1380

[Dan-Burns]

Thank you, @zhang-ivy. I assume I can change the line in exceptions_sterics_energy_expression from: 'reff_sterics = sigma*((softcore_alpha*(1.0-({0}))^softcore_b + (r/sigma)^softcore_c))^(1/softcore_c);')\ .format(lambda_variable_name) to: 'reff_sterics = sigma*((softcore_alpha*(1.0)^softcore_b + (r/sigma)^softcore_c))^(1/softcore_c);') I will see what happens. Dan