A list of molecules calculations examples with Hartree Fock model provided with the software:
AlCl3, Ar, Benzene, BF3, C2, C2H2, C2H2+, C2H4, C2H5OH, C3, C3H4, C3N, C5F8, C5HF7, CaF, CaF+, CF, CF2, CF4, CFCs, CH, CH+, CH4, CN, CO, CO2, CO2+, COS, CS, CN, F2O, H2, H2+, H2O, H2S, HBr, HCHO, HCN, HCONH2, HCP, HNC, I2, N2, NH3, NO2, O2, O3, PH3, SF6, SiF2, SiH4, SiO, SO2, C2F2, C2F4, C2F6, C3F8, C3, C4, C2, CF3, CF4, CF, F2.
Align Water Molecule Example
The Align feature in Quantemol-N allows you to calculate cross-sections for a molecule oriented in a particular way, rather than as an average of all orientations. This feature can be useful for example when working with laser aligned gases or liquids or thin film coating of a substance with aligned molecules.
The outputs can show how the double differential cross sections change as a function of both molecular alignment, and also as a function of energy. See the demo for the water molecule here
Target state potential energy curves, N2+
Figure below shows target state potential energy curves for the ground state of N2+ and the first two excited states. The solid line shows the calculated curves and the broken line experimental data (Lofthus and Krupenie, J. of Phys. and Chem. Ref. Data, Vol. 6, 1977). The target state energy curves were calculated using the scattering configuration interaction code SCATCI with multi-configuration self-consistent field orbitals and the cc-pVQZ basis set of Dunning (Dunning J. Chem. Phys. Vol. 90, 1989). The calculated curves are highly accurate in the equilibrium region with a maximum difference from experimental energies of around 0.08 eV and a maximum difference in equilibrium positions of less than 0.01 Angstrom.
Electron impact excitation cross-section of N2+
Figure below shows the electron impact excitation cross-section of N2+ for excitations between the vibrational ground state and the vibrational ground state of the second lowest excited state at equilibrium geometry. A comparison with experimental values is also given (Crandall et al. Phys. Rev. Vol. 9, 1974). The cross-section was calculated using the R-matrix method using the target state displayed in the (previous) figure. The N+1 scattering calculation used a 40,000 dimensional Hamiltonian to calculate the eigen-energies of the continuum scattering states. The R-matrix method was then used to propagate these solutions to their asymptotic origin and the cross-sections were calculated. A Gaussian fit was applied to the data. The agreement with experimental values above ~7 eV is good.
Bound state curves of N2+
Figure shows resonant and bound state curves of N2+ for the triplet Pi-u symmetry. The resonant state curves (above the ground state) and bound state curves (below the ground state) were calculated using the target state curves in the (previous) figure and using programs RESON and BOUND in the outer region section of the R-matrix calculation. The program RESON also provides information on resonance widths which is useful for calculating processes such as dissociative recombination. This gives this technique of calculating bound state curve crossing points of ions a distinct advantage over other ab-initio methods which do not provide information on the widths. The figure also shows the level detail which can be achieved when calculating bound states using a scattering calculation such as the R-matrix method.
Note: The N2+ calculations were performed by D. Little, J. Tennyson, private communication, University College London
The cross-sections were used in joint project with Tokyo Electron. More details bout this project can be found here.