HyperChem 5.02 Release Notes

Bug Fixes Since HyperChem 5.01

ISIS/Sketch (*.SKC) files

ISIS/Sketch files (*.SKC) can be cut and pasted, saved and loaded.

Printing under Windows NT 4.0

HyperChem 5.01 quietly failed to print, or printed blank pages under Windows NT 4.0 for certain printers.

Molecular dynamics crash

In HyperChem 5.01, molecular dynamics runs with molecular mechanics methods and a non-zero cool time would result in corrupt atomic positions, and an inevitable crash. Patches for MMPLUS.EXE and NEWTON.EXE for this problem are available on our web site, as well as being fixed with this upgrade patch.

Molecular dynamics heat, run, and cool times

HyperChem 5.01 would refuse to run molecular dynamics simulations with a zero run time but non-zero heat or cool times.

Data corruption during large-molecule dynamics or optimization

In certain highly variable circumstances usually involving large molecules and either molecular dynamics or geometry optimization, 5.01 would terminate with a large random (sometimes negative) cycle count displayed on the status bar, most of the atomic coordinates changed to zero, and the remainder scrambled.

Crash painting ESP onto density isosurface

In certain unusual circumstances, repeated plotting of an ESP-painted isosurface could crash HyperChem 5.01.

Painted isosurface image disappears under NT 4.0

Trying to display an ESP-painted isosurface under the Windows NT 4.0 operating system would sometimes cause the display to go blank.

"Cut" or "Copy" toolbar buttons hang geometry optimization

Using the new toolbar buttons "Cut" and "Copy" could hang 5.01. They are deactivated during backend computations in 5.02.

Cannot minimize window while recording AVI

Attempting to minimize the HyperChem window while making an AVI video recording would crash HyperChem 5.01. Minimization is disabled during AVI recording in 5.02.

"Restart" in Monte Carlo calculations

If the "Restart" option was set from a previous molecular dynamics or Langevin calculation, Monte Carlo calculations would frequently fail with the message "Wrong index returned by uniform random number generator."

Contour plot intervals incorrect

Contour plots with user-chosen start and increment values were not drawn correctly.

Restraint angles of 0 and 180 degrees

Bond angle restraints (for optimizations etc., NOT constraints for the model builder) were not permitted to assume values of exactly 0 or 180 degrees in 5.01.

Limit on number of 4-member rings in molecular mechanics

The number of 4-member rings which can be handled by MM+ has been increased from 40 to 400.

Latest driver software for hardware locks

In January 1997 Rainbow Technologies released new device driver software for the Sentinel and NetSentinel hardware locks. Version PD-5.3 is included with HyperChem 5.02 in the "Drivers" folder. These new drivers should, among other things, eliminate compatibility problems between the hardware lock and printers such as the HP LaserJet 5 which use ECP parallel port technology.

Network clients losing license may recover gracefully

If an instance of HyperChem 5.02 using a network lock loses its license due to a license server crash or a license timeout, the user is presented with the option of trying to reestablish a network license rather than being forced to exit and lose work.

Network clients failing to release licenses

Copies of HyperChem 5.01 obtaining licenses from a network license manager would sometimes fail to notify the license manager on closing if the network was too busy. HyperChem 5.02 will retry several times if the notification fails, which should reduce the frequency with which the license manager needs to be reset.

Starting HyperChem by clicking on a HIN file will find chem.scr

HyperChem 5.02 will look for and execute a script file named 'chem.scr' in the ChemExeDir (typically, C:\Hyper5\Program). Version 5.01 would only do this if the current working directory was ChemExeDir, which is not the case if you start HyperChem by double-clicking on a HIN file icon in Windows Explorer, for instance. If your 'chem.scr' contains a 'load-user-menu' command, such as in CDK\Menus\Chemplus.scr, you should edit the argument to include the absolute path of the .mnu file. For example, load-user-menu C:\Hyper5\Program\chemplus.mnu.

PM3 capping-atom parameters for carbon supplied

PM3 capping-atom parameters for carbon were inadvertently omitted from the PM3 parameter files in 5.01. They are supplied in this release. (Runfiles\pm3_1.abp, pm3_2.abp, pm3_3.abp).

Script variables and commands

Bugs have been fixed involving the following script/DDE variables: is-ring-atom serial-number semi-empirical-method huckel-scaling-factor ci-criterion ci-occupied-orbitals ci-unoccupied-orbitals ci-excitation-energy coordinates

Warning suppressed on changing force-fields via script or DDE

Upon changing from one molecular mechanics force field to another, a warning message "Recalculate atom type. Old types will be lost. Proceed?" is issued. This message was impossible to suppress when changing force fields via a script or DDE command in 5.01. In 5.02 it is automatically suppressed when using scripts or DDE commands.

HyperChem 5.02 Build Notes

Release 5.02 of HyperChem was created with a new compiler. We believe this compiler results in Release 5.02 being more stable than Release 5.01. However, we have not yet performed compiler optimizations for this new compiler and Release 5.02 may be somewhat slower than Release 5.01 for compute intensive floating point operations.

A future Maintenance Update will address this compiler optimization. If performance is a prime consideration in your use of HyperChem, you may not want to update from Release 5.01 to Release 5.02 but wait for the next Maintenance Update, 5.02 to 5.03.