OpenMM 7.4.0

A major focus of this release is performance. Not so much the speed of running a simulation, but everything else surrounding it. Creating a System from a ForceField is much faster than before. Building water boxes and membranes are both much faster. Loading PDB files is a bit faster. In certain situations, creating a new Context can be a lot faster. And so on.

This release adds classes for simulated tempering and metadynamics. These are the same classes that were previously available as separate downloads. They are now bundled as standard features.

This release adds support for PPC processors. This is mainly to support Summit, since a lot of people want to run on there.

We've also added a major feature that involves a huge amount of new code, but won't yet actually be useful for most people: we've implemented all the functional forms used in the HIPPO force field. This is a new force field under development by Jay Ponder's group, which is designed to be the successor to AMOEBA. It should be a lot more accurate and more transferable, while also being faster. They're still working on parametrizing the force field, so you can't yet run simulations with it, but we have all the code ready to support it once the force field is finished.