Version 1.9.0 Major Release

New features since v1.8.1

Internal coordinate Hessian target (Hyesu Jang)

• This target involves fitting the Hessian, transformed into a primitive internal coordinate system.
• The QM input data is a Hessian matrix in Cartesian coordinates.
• The MM Hessian is computed after a local energy minimization.
• The geomeTRIC package is used to transform the Hessian matrix into internal coordinate prior to computing the objective function.

Virtual sites in SMIRNOFF/OpenFF (Simon Boothroyd)

• Includes TIP4P example calculation

Support for LocalCoordinatesSite in OpenMM (Josh Horton)

Minor changes

• Add option to delete microiteration outputs when searching over Hessian diagonal (Simon Boothroyd)
• A couple of small bug fixes (Pavan Kumar and Mateusz Bieniek)