A Projector Augmented Wave (PAW) code for electronic structure calculations, Part I: atompaw for generating atom-centered functions
The computer program atompaw generates projector and basis functions which are needed for performing electronic structure calculations based on the Projector Augmented Wave (PAW) method. The program is applicable to materials throughout the periodic table. For each element, the user inputs the atomic number, the electronic configuration, a choice of basis functions, and an augmentation radius. The program produces an output file containing the projector and basis functions and the corresponding matrix elements in a form which can be read be the pwpaw PAW code. Additional data files are also produced which can be used to help evaluate the accuracy and efficiency of the generated functions.
Ethological communication permits the exchange of context-specific information among mammals. In recent literature, many investigations have been performed on behavioral responses but little is known about neurophysiological pattern activation. In this study we investigated neuron patterns in response to ultrasound vocalizations, mapping the auditory cortex in order to find the specific activation area which best fits with perceived vocalization in rats. Receptive fields were directly reached through implanted electrodes in order to record the ultrasound information into the auditory system, bypassing sense organs. Techniques based on Principal Component Analysis and statistical analysis were used to investigate the tonotopic organization exploiting local field-potential classifications. The results, according to the sensitivity index, identified two tonotopic fields with a gradient from high-to-low best frequency using unsupervised classification algorithm.