The features of the Student Edition of HyperChem are identical to those of the Professional Product apart from the limitations on number of atoms as described elsewhere. Some of these new features are:

**Density Functional Package**

Density Functional Theory (DFT) has been added as a basic computational engine to complement Molecular Mechanics, Semi-Empirical Quantum Mechanics and *Ab Initio* Quantum Mechanics. This new computational method comes with full capabilities including first and second derivatives so that all the capabilities of other earlier engines are also available with DFT. These include geometry optimization, infrared and optical spectra, molecular dynamics, Monte Carlo, etc.

A full complement of exchange and correlation functions is available, including eight exchange functionals and eight correlation functionals that can be combined in any fashion. Also included are four combination or hybrid functions, such as the popular B3-LYP or Becke-97 methods. A choice of various integration grids, controlling the method’s accuracy, is available to the user.

**NMR Simulation**

The HyperNMR package has been integrated into the core of HyperChem. This package allows for the simulation of NMR spectra. An accurante semi-empirical tailored specifically to NMR allows rapid interactive computation of NMR shielding constants (chemical shifts) and coupling constants for molecules as large as proteins. Based on a solution of the quantum mechanical coupled-Hartree-Fock equations rather than simple database lookup, this package allows full exploration of NMR parameters in any situation, such as a new or novel chemical environment where simple database interpolation is impossible.

When appropriate, the NMR parameters can be integrated into a spin Hamiltonian to predict and display the full one-dimensional NMR spectra. The spectra can be manipulated to add line widths so as to simulate experimental spectra.

**Database Package**

** **A full database capability is integrated into HyperChem 8. This includes database search and retrieval of molecules for subsequent molecular modeling calculations as well as the storing of computed properties and optimized structures of your molecules in a new database. Included with the product is a sample database of 10,000 molecules that have previously been optimized with HyperChem. The sample database that is included is representative of common chemical compounds and can be used in a variety of ways associated with research in computational chemistry.

Database retrieval is simple and interactive and a variety of methods can be used to search a database, including a search for 2D or 3D structure. In conjunction with HyperChem’s scripting capability, a generic search based on appropriate computed properties is possible. That is, a question such as, “Give me all molecules whose stored or computed value of X is between x-d and x d” is possible.

**Computational Capabilities**

Use HyperChem to explore quantum or classical model potential energy surfaces with single point, geometry optimization, or transition state search calculations. Include the effects of thermal motion with molecular dynamics, Langevin dynamics or Metropolis Monte Carlo simulations. User defined structural restraints may be added.

**Types of Calculations**

- 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.