HyperChem 5.11 Release Notes

Bug Fixes Since HyperChem 5.1

DDE fix for ChemPlus and HyperChem interaction¹

This part of the patch addresses the long standing problem of instability when running ChemPlus with HyperChem 5.1, and the problem of HyperChem 5.1 carrying out long computations and halting with messages like "Low Memory..." or "Error initializing DDEML.DLL...". This behavior has been cured and now you can run multiple instances of HyperChem or HyperChem with any other module (such as Conformational search) using DDE communications safely, without crashing and having to reboot Windows 95.

Fix for incorrect Chirality labeling:

Incorrect labeled chiral centers can now be identified correctly. The new revision now correctly follows Cahn-Ingold Prelog rules for determining chirality.

Incorrect usage of atomic charges in MM+ module fixed

MM+ can now correctly handle calculations using the option "atomic charges" even  when a charge of zero is present on atoms. Earlier incorrect behavior showed up as only some electrostatic terms being computed.

 Typographical correction to the ChemPlus.mnu¹

A typographical error in the ChemPlus.mnu file in the CDK distribution has been corrected. The incorrectly typed command "menu-isosurface-control" has been replaced by the correct command "menu-display-isosurface". 

Maximum file size limit raised for integrals file in HyperGauss module

Recent modifications to the code now allow HyperGauss backend module of HyperChem 5.1 Pro to write electron integral files with sizes in excess of 2.1 Gigabytes, as permitted by Windows NT and FAT32 (OSR2) releases of Windows 95 and Windows 98. This should prove beneficial to users with larger basis set requirements. 

Running backends on remote Unix hosts on different subnets

The network feature of HyperChem 5.11 where a user can run proper UNIX backends on a remote UNIX host on different subnets is now activated. This feature will allow use of backends such as eht, gauss, mmplus, ndo and newton specifically built for this version to be run on IRIX, HP-UX and AIX flavors of UNIX platforms. These backends will be released in the very near future.

Incomplete registry entry of filters for users on Windows NT fixed

HyperChem when invoked by a user under Windows NT does not correctly make all the registry entries for Filters and Amber. It is correctly done only when invoked by the user 'Administrator'. This behavior has been corrected in HyperChem 5.11.

Updated HAPI.DLL released¹

An updated HAPI.DLL is supplied which fixes a problem in The Visual Basic routine hbQueryTxt. Calling hbQueryTxt with the old version of HAPI.DLL will cause an invalid page fault if it tries to return a result longer than the user has allocated space for with a fixed-length string. Since fixed-length strings are not normal VB programming practice, this would happen on most uses of the routine.

¹ These changes do not apply to HyperChem 5.1 Standard