From VanBeek et al. Biophys J. (2007) 92, 4168-4178 MASS OA 16.00 0.465 same as gaff os and parm99 BOND CA-OA 372.40 1.373 same as gaff ca-os CA- O 648.00 1.214 same as gaff c -o ANGLE CA-CA-OA 69.800 119.200 same as gaff ca-ca-os CA-CA-O 70.900 123.430 same as gaff ca-ca-o CA-C -O 68.700 123.440 same as ca-c -o in gaff CA-C -O2 68.700 123.440 same as ca-c -o in gaff CA-OA-CA 63.600 118.960 same as GAFF ca-os-ca CA-C -N 69.400 112.030 same as GAFF ca-c -n DIHE CA-CA-OA-CA 4 14.500 180.000 2.000 Same as gaff X-ca-ca-X and because M. Zwier found ~18 when hand fitting IMPROPER NONBON OA 1.6837 0.1700 OPLS ether e.g. same as gaff os