In order to represent the potential energy function over the whole range of R, many potentialenergy functions have been proposed. In the present paper, we employ many potential energyfunctions, to use Numerov method for solving the nuclear Schrödinger equation for the IFmolecule, as an example of a heteronuclear diatomic molecules. Then we determine thespectroscopic constants eω , e e x ω , e B , and eα of the IF molecule from vibrational and vibrationrotationlevels obtained from solution of the nuclear Schrödinger equation. Finally, bycomparison of obtained values with the experimental ones, their accuracy rate is determined aswell as their deviation percentages from experimental values. تفاصيل المقالة

Densities and excess molar volume of the binary and ternary mixtures formed by nbutylacetate+ 1-butanol + 1,2-butanediol were measured at (298.15, 303.15, and 308.15) K forthe liquid region and at ambient pressure (81.5) k Pa , for the whole composition range. Theexcess molar volumes,VmE and excess partial molar volume ViE ,were calculated fromexperimental densities.The excess molar volumes are positive over the mole fraction rage forbinary mixtures of n-butylacetate (1) + 1-butanol (2) and n-butylacetate (2) + 1,2-butanediol (3)and increase with increasing temperatures from (298.15 to 308.15)K. The excess molar volumesof 1-butanol (1) + 1,2-butanediol (3) are negative and decrease with increasing temperaturesfrom (298.15 to 308.15)K..The experimental data of constitute were correlated as a function ofthe mole fraction by using the Redlich–Kister equation for binary and , Cibulka, Jasinski andMalanowski , Singe et al, Pintos et al , Calvo et al, Kohler, and Jacob - Fitzner for ternarymixture ,respectively. The experimental data of the constitute binaries are analyzed to discuss thenature and strength of intermolecular interactions in these mixtures. تفاصيل المقالة