Useful in not only predicting the electronic absorption spectra of conjugated molecules but even the actual colour of a simulated dye solution
Silverdale Scientific announce PiSystems XTE - a unique chemical database for three-dimensional molecular structures with integrated artificial intelligence.
PiSystems is described as the fastest, most reliable, and at the same time most user-friendly quantum chemical program for the calculation of an organic molecule's electronic spectra and colour.
It's a must for all people working in the field of synthetic science, says Silverdale.
The generation of new molecules in PiSystems is extremely simplified so that the user may either modify pre-generated fragments or alternatively draw them from scratch in a very user-friendly 'drag and draw' fashion.
Heteroatoms can be added, selected from a given set for which SCF-parameters are available.
Experienced users may modify these parameters within limits which are controlled by the program.
At any time the draft may be idealised by an extremely fast geometry-optimiser.
Although the program is focused on planar molecules, parts of them may be rotated about exocyclic bonds.
The results of the SCF-CI calculations in PiSystems are graphically presented in various windows, allowing their immediate visual interpretation.
Each graphic can be optionally set up in various fashions, eg black on white or vice versa and/or coloured or black and white.
An elaborate online help provides information on the selected graphic at a click of the right mouse button.
PiSystems's particular strength is its accuracy in predicting electronic absorption spectra of conjugated molecules.
The calculated spectra are visualised in a close-to-reality fashion by overlaying vibrational bands, their relative intensities being calculated by standard methods.
Optionally, the spectral range to be visualised and/or the direction of the spectrum can be altered.
PiSystems is most useful in not only predicting the electronic absorption spectra of conjugated molecules but even the actual colour of a simulated dye solution.
For this purpose, PiSystems applies standard Cielab methods for the translation of a calculated close-to-reality absorption spectrum into a simulated concentrations series in an inert media.
Beyond the ease of the calculation of reliable electronic absorption spectra of conjugated molecules, PiSystems also provides insight into the dynamics of the electronic excitation within the molecules.
For instance, different views of the effect of an electronic excitation are available in a variety of graphical forms such as those illustrating the direction of the transition moment for the lowest electronic excitation and its calculated intensity, or the effect of the lowest electronic absorption upon the electron density distribution, or the effect of the lowest electronic absorption upon the bond strengths.
Beyond the reliable prediction of electronic absorption spectra of conjugated molecules and the dynamic influences of the excitation within the molecules, PiSystems can also support the user in synthesis planning.
If for example he wants to know where to add a certain substituent in order to shift the long wave absorption band in a certain direction, or if he is interested in the most reactive centre of a conjugated molecule towards a nucleophilic or electrophilic reagent, PiSystems provides the answer at a mouse click, says Silverdale.
