Structure Input and Manipulation
Building molecules with HyperChem is simple: just choose an element from the periodic table, and click and drag with the mouse to sketch a structure. Mouse control of rotation around bonds, stereochemistry, and "rubber banding" of bonds makes changing structures easy. Extensive selection, highlighting, and display capabilities make it easy to focus on areas of interest in complex molecules.
- Single point calculations determine the molecular energy and properties for a given fixed geometry.
- Geometry optimization calculations employ energy minimization algorithms to locate stable structures. Five minimization algorithms are provided.
- Vibrational frequency calculations find the normal vibrational modes of an optimized structure. The vibrational spectrum can be displayed and the vibrational motions associated with specific transitions can be animated.
- Transition state searching locates the metastable structures corresponding to transition states using either Eigenvector Following or Synchronous Transit methods. Molecular properties are then calculated.
- Molecular dynamics simulations compute classical trajectories for molecular systems. Quantum forces can be used to model reactive collisions. Heating, equilibration, and cooling periods can be employed for simulated annealing and for studies of other temperature dependent processes. Both constant energy and constant temperature simulations are available.
- Langevin dynamics simulations add frictional and stochastic forces to conventional molecular dynamics to model solvent collisional effects without inclusion of explicit solvent molecules.
- Metropolis Monte Carlo simulations sample configurations from a statistical ensemble at a given temperature and are useful for exploring the possible configurations of a system as well as for computing temperature dependent equilibrium averages.
- Excited states via singly-excited configuration interaction (CI).