The present work devotes to studying the electric properties: electric quadrupole moment and electric field gradient (EFG) of molecules PdH and (PdH)-2 based on the full relativistic theory. It is the first time to ex...The present work devotes to studying the electric properties: electric quadrupole moment and electric field gradient (EFG) of molecules PdH and (PdH)-2 based on the full relativistic theory. It is the first time to explore that the force constants are essentially caused by electric field gradients, and indirectly with spectroscopic data. If EFG is positive, zero or negative, then the will be positive, zero or negative. Therefore, second order force constants are adjustable to changing the intensity of EFG.展开更多
The present calculations of three geometry conformation for tetrahydrofuran (THF, C4H8O) using density functional theory lead to the energy level sequence E(C1) E(Cs) E(C2v), where, both the geometry symmetry C2v and ...The present calculations of three geometry conformation for tetrahydrofuran (THF, C4H8O) using density functional theory lead to the energy level sequence E(C1) E(Cs) E(C2v), where, both the geometry symmetry C2v and Cs are probably a transition structure. The C1 symmetry is the equilibrium conformation, for its energy is the lowest one and it is only possible without the negative harmonic frequency. In C1 conformation, the 4 of carbon atoms C and oxygen atom O constitute a curved surface or the helix surface. The tetrahydrofuran molecule can be as a simple prototype of deoxyribose and has been reviving a quite deal of interest in radiation damage research. It is well known that the sugar ring of deoxyribose is considered as a plane in most of the references. If the equilibrium conformation of THF is C1 symmetry with the helix surface, and for the same reason, the sugar ring of deoxyribose would be also the helix surface;this probably causes the double helix of DNA. It is hardly believed that the sugar ring is a plane in deoxyribose.展开更多
文摘The present work devotes to studying the electric properties: electric quadrupole moment and electric field gradient (EFG) of molecules PdH and (PdH)-2 based on the full relativistic theory. It is the first time to explore that the force constants are essentially caused by electric field gradients, and indirectly with spectroscopic data. If EFG is positive, zero or negative, then the will be positive, zero or negative. Therefore, second order force constants are adjustable to changing the intensity of EFG.
文摘The present calculations of three geometry conformation for tetrahydrofuran (THF, C4H8O) using density functional theory lead to the energy level sequence E(C1) E(Cs) E(C2v), where, both the geometry symmetry C2v and Cs are probably a transition structure. The C1 symmetry is the equilibrium conformation, for its energy is the lowest one and it is only possible without the negative harmonic frequency. In C1 conformation, the 4 of carbon atoms C and oxygen atom O constitute a curved surface or the helix surface. The tetrahydrofuran molecule can be as a simple prototype of deoxyribose and has been reviving a quite deal of interest in radiation damage research. It is well known that the sugar ring of deoxyribose is considered as a plane in most of the references. If the equilibrium conformation of THF is C1 symmetry with the helix surface, and for the same reason, the sugar ring of deoxyribose would be also the helix surface;this probably causes the double helix of DNA. It is hardly believed that the sugar ring is a plane in deoxyribose.
