CO基态的偶极矩的量化计算研究

运用MOLPRO软件,采用基组6-31G,6-31G（d）,6-31G（2d,3f）,aug-cc-pv5z, 方法HF(Hartree-Fock)、CASSCF（完全活性空间自洽场）和MRCI（多参考组态相互作用）,计算了CO的基态 的偶极矩随核间距变化的12条曲线,与基于实验光谱数据的偶极矩在平衡位置的值以及在平衡位置的斜率进行了比较,结果表明,采用MRCI方法,aug-cc-pv5z基组的偶极矩曲线最为准确．平衡位置斜率的偏差小于1%．接着采用MRCI方法,aug-cc-pv5z基组计算得到了CO基态的势能曲线,进而通过求解核的薛定谔方程得到振动能级以及分子力常数,分子力常数与实验值符合的很好．     

CO基态的偶极矩的量化计算研究

运用MOLPRO软件,采用基组6-31G,6-31G(d),6-31G(2d,3f),aug-cc-pv5z,方法HF(Hartree-Fock)、CASSCF(完全活性空间自洽场)和MRCI(多参考组态相互作用),计算了CO的基态X1Σ+的偶极矩随核间距变化的12条曲线,与基于实验光谱数据的偶极矩在平衡位置的值以及在平衡位置的斜率进行了比较,结果表明,采用MRCI方法,aug-cc-pv5z基组的偶极矩曲线最为准确.平衡位置斜率的偏差小于1%.接着采用MRCI方法,aug-cc-pv5z基组计算得到了CO基态的势能曲线,进而通过求解核的薛定谔方程得到振动能级以及分子力常数,分子力常数与实验值符合的很好.     

High order vibrational matrix elements for diatomic molecules; dipole moment function and transition moments of CO

The fifth and sixth-order contributions to the vibrational matrix elements are obtained for the transitions v→v'(v'?v+4) using an eight power internuclear Dunham potential and a quartic power series expansion of the dipole moment function. The results for the dipole moment coefficients M₀ to M₄ of CO and the transition moments R_v^v' (with v=5, 10, 20) deduced from a calculation including succesively third, fourth, fifth and sixth-order perturbation theory are compared. The validity of these results is discussed.Using a quintic dipole moment function, general expressions for the vibrational matrix elements corresponding to the transitions v→v'(v'? v+5) are also presented and the influence of these contributions on the calculation of the dipole moment coefficients as well as the hot band transition moments of CO is shown.     

Electric dipole moment function and line intensities for the ground state of carbon monxide

An accurate electric dipole moment function(EDMF) is obtained for the carbon monoxide(CO) molecule(X1+Σ)by fitting the experimental rovibrational transitional moments. Additionally, an accurate ab initio EDMF is found using the highly accurate, multi-reference averaged coupled-pair functional(ACPF) approach with the basis set, aug-cc-p V6 Z, and a finite-field with ±0.005 a.u.(The unit a.u. is the abbreviation of atomic unit). This ab initio EDMF is very consistent with the fitted ones. The vibrational transition matrix moments and the Herman–Wallis factors, calculated with the Rydberg–Klein–Rees(RKR) potential and the fitted and ab initio EDMFs, are compared with experimental measurements. The consistency of these line intensities with the high-resolution transmission(HITRAN) molecular database demonstrates the improved accuracy of the fitted and ab initio EDMFs derived in this work.     

On the magnetic dipole moment of the153Tb ground state

Temperature dependence of the angular distribution anisotropy of the 212·0 keV gamma-ray following the decay of¹⁵³Tb oriented in a gadolinium host was measured at temperatures from 16 to 70 mK. Magnetic dipole hyperfine splitting parameter a₀ for¹⁵³Tb(Gd) and magnetic dipole moment of the¹⁵³Tb ground state were estimated to be ¦a ₀¦1·2×10^–5 eV and ¦¦3·1 nuclear magnetons, respectively.Authors are indebted to Dr. N. A. Lebedev, Yu. V. Yushkewich and the staff of the JINR synchrocyclotron for the preparation of the¹⁵³Tb activity. The participation of Ing. L. Mare, J. Ferencei and S. I. Antonov in the measurements is also acknowledged.     

Laser-Stark spectrum of NH3 with the CO laser: Determination of the ground state dipole moment

Results from analysis of sub-Doppler laser-Stark spectra of ¹⁴NH₃ obtained using a CO laser and an intracavity Stark cell are given. Over 1500 Lamb dips have been identified, associated with about 200 NH₃ lines. The data are analyzed to determine relative frequencies between the laser lines and the NH₃ lines. In favorable cases this can be done with an accuracy of 5–10 MHz. Analyses of a portion of the data yield the expression for the ground state dipole moment in Debye, μ^H(J, K) = 1.47182(30) + 1.654(190) × 10^?4J(J + 1) ? 3.095(300) × 10^?4K².     

The sign of the magnetic dipole moment of the ground state of122I

The sign of the nuclear magnetic dipole moment of the ground state of¹²²I has been determined to be positive using a novel experimental technique. The technique investigates the asymmetry of positron emission by detecting the 511 keV gamma-rays produced on the annihilation of the positrons. The method would appear to have general validity for studying the sign of the magnetic moment in other cases where theβ ⁺ decay is relatively simple.     

The183Re ground state dipole moment and nuclear spin-lattice relaxation of Re in Fe

The hyperfine interaction of the system¹⁸³Re(70d)Fe has been investigated with the NMR/ON technique. With the hyperfine field valueB _hf(ReFe)=–76.0(1.5) T the ground state magnetic moment was determined as: (5/2⁺,¹⁸³Re)=+3.12(6) _N. The field dependent nuclear spin-lattice relaxation time has been measured. The result for the high-field relaxation rateR _exp=1.65(5)·10^–15 T ²s K^–1 is explained in terms of indirect spin-wave interaction.     

Dipole moment function and vibration-rotation matrix elements of HCl35 and DCl35

The infrared intensity measurements and molecular beam electric resonance dipole moment measurements for HCl and DCl have been reviewed. A method not previously exploited is used to determine infrared matrix elements from the electric resonance dipole moment measurements. A ‘best’ set of matrix element values was selected for HCl and from these the M_i-coefficients of a polynomial dipole moment approximation were determined; M₀ = 1.0935±0.0007 D, $\text{M}{}_1\text{= 0.947±0.023 D/}\text{A}\text{?}$, $\text{M}{}_2\text{= 0.015±0.041 D/}\text{A}\text{?}{}^2$, $\text{M}{}_3\text{= -0.814± 0.116 D/}\text{A}\text{?}{}^3$. Calculations using this dipole moment function for both HCl and DCl are shown to give good agreement with available band strength and vibration-rotation interaction factor measurements. RKR potentials are also calculated for both molecules.     

Computation of electric dipole matrix elements for hydrogen fluoride

The electric dipole matrix elements of hydrogen fluoride have been calculated by numerical integration for transitions involving large quantum numbers υ, J. Overtones have been included through Δυ = 5. Molecular wave functions obtained by numerical integration of the Schrödinger equation were used. The influence of the mechanical motion on the matrix elements has been determined for Morse and Rydberg-Klein-Rees (RKR) potential functions. The influence of the electric dipole-moment function approximations has been investigated by a comparison of matrix elements obtained with approximations having the form of a truncated polynomial and a wave-function expansion. The inaccuracies in the matrix elements caused by uncertainties in the dipole-moment coefficients have been investigated.     

Magnetic moment and electric quadrupole moment of the anomalous186Ir ground state

The ground state nuclear moments of¹⁸⁶Ir (j ^π=5⁽⁺⁾) have been determined with NMR on oriented¹⁸⁶Ir in Ni as |μ|=3.80 _?0.02 ^+0.12 μ _n andQ=?3.00 (15)b. The quadrupole moment is consistent with an anamolousj ^π K=5⁺0 or 5⁺1 ground state configuration. The explanation of the magnetic moment in terms of pure 5⁺0 or 5⁺1 configurations would require a high collectiveg _R-factor ofg _R≧0.76. On the other hand the magnetic moment can be explained with a “normal”g _R and a mixed ground state configuration.     

Determination of parameters of the dipole moment of the CO2 molecule

Analytic expressions are obtained for vibrational transition moments of the first, second, and third orders using the eigenfunctions in the second-order perturbation theory. These expressions can be used to solve the inverse electrooptical problem for the ¹²C¹⁶O₂ molecule. The resonance interactions were taken into account by solving secular equations. The mixing coefficients for the eigenfunctions were calculated with an accuracy of 0.1%. The experimental data on purely vibrational transition moments 〈μ〉² used in the solution were obtained by averaging the data available in the literature with the weights that are inversely proportional to the error, resulting in mean-square deviations of (0.1–10)%. Five parameters of the dipole moment of the Σ _u symmetry were calculated using 29 values of the transition moments; five parameters of the π_u symmetry were calculated using 27 values of the transition moments. The accuracy of the solution of the inverse problem is characterized by the quantity Q=[Σ(δμ _i ^(theor) /δμ _i ^(exp) )²/(n-m)]^1/2, where δμ _i ^(theor) is the deviation of calculations from the experiment, δμ _(exp) ⁱ is the experimental error, n is the number of the experimental data used, and m is the number of parameters smaller than unity. __________ Translated from Optika i Spektroskopiya, Vol. 88, No. 5, 2000, pp. pp719–732. Original Russian Text Copyright ? 2000 by Kolomiĭtsova, Lyaptsev, Shchepkin.     

Nuclear magnetic moment of the 57Cu ground state

The nuclear magnetic moment of the ground state of (57)Cu(Iota(pi) = 3/2(-), T(1/2) = 196.3 ms) has been measured to be /mu((57)Cu)/ = (2.00 +/- 0.05)mu(N) using the beta-NMR technique. Together with the known magnetic moment of the mirror partner (57)Ni, the spin expectation value was extracted as = -0.078 +/- 0.13. This is the heaviest isospin mirror T = 1/2 pair above the (40)Ca region for which both ground state magnetic moments have been determined. The discrepancy between the present results and shell-model calculations in the full f p shell giving mu((57)Cu) approximately 2.4mu(N) and approximately 0.5 implies significant shell breaking at (56)Ni with the neutron number N = 28.     

Ab initio dipole moment and theoretical rovibrational intensities in the electronic ground state of PH3

We report a six-dimensional CCSD(T)/aug-cc-pVTZ dipole moment surface for the electronic ground state of PH₃ computed ab initio on a large grid of 10 080 molecular geometries. Parameterized, analytical functions are fitted through the ab initio data, and the resulting dipole moment functions are used, together with a potential energy function determined by refining an existing ab initio surface in fittings to experimental wavenumber data, for simulating absorption spectra of the first three polyads of PH₃, i.e., (ν₂, ν₄), (ν₁, ν₃, 2ν₂, 2ν₄, ν₂ + ν₄), and (ν₁ + ν₂, ν₃ + ν₂, ν₁ + ν₄, ν₃ + ν₄, 2ν₂ + ν₄, ν₂ + 2ν₄, 3ν₂, 3ν₄). The resulting theoretical transition moments show excellent agreement with experiment. A line-by-line comparison of the simulated intensities of the ν₂/ν₄ band system with 955 experimental intensity values reported by Brown et al. [L.R. Brown, R.L. Sams, I. Kleiner, C. Cottaz, L. Sagui, J. Mol. Spectrosc. 215 (2002) 178-203] gives an average absolute percentage deviation of 8.7% (and a root-mean-square deviation of 0.94 cm⁻¹ for the transition wavenumbers). This is very remarkable since the calculations rely entirely on ab initio dipole moment surfaces and do not involve any adjustment of these surfaces to reproduce the experimental intensities. Finally, we predict the line strengths for transitions between so-called cluster levels (near-degenerate levels formed at high rotational excitation) for J up to 60.     

Nuclear magnetic moment of 57Cu ground state

The nuclear magnetic moment of the ground state of ⁵⁷Cu(I^π = 3/2^-, T_1/2 = 196.3 ms) has been measured to be |μ(⁵⁷Cu)| = (2.00 ±0.05) μ_N using the β-NMR technique. Together with the known magnetic moment of the mirror partner ⁵⁷Ni, the spin expectation value was extracted as = -0.78 ± 0.13. Discrepancy between present results and shell model calculations in the full fp shell implies significant shell breaking at ⁵⁶Ni with the neutron number N = 28.     

The magnetic dipole moment of the 91 keV state of147Pm

The magnetic dipole interaction of the 91 keV state of¹⁴⁷Pm in an environment of metallic neodymium has been investigated by a time-differential perturbed angular correlation (TDPAC) experiment. The measurement was performed in an external magnetic field of 2.94 (3) T at room temperature. From the Larmor precession frequency the magnetic dipole moment of the 91 keV state is derived as =+3.22(16) _K. The enhancement of the external magnetic field by the paramagnetic 4f shell determines the ionicity of the Pm ion as Pm³⁺ in metallic and as Pm⁴⁺ in non-metallic sources.     

The magnetic dipole moment of the 150 keV state of177Lu

The magnetic dipole interaction of the 150 keV state of¹⁷⁷Lu in an environment of metallic ytterbium has been investigated by time-differential perturbed angular correlation experiments. The measurements were performed in an external magnetic field of 0.4 T at room temperature. Two independent measurements at different - cascades give the same Larmor precession frequency. From the weighted average the magnetic dipole moment of the 150 keV state is derived as =+5.5(3) _K. From the angular correlation coefficient A₂₂=–0.042(7) of the (139–150) keV - cascade the mixing ratio =+0.21(4) is deduced. The coefficient A₂₂=+0.015(7) of the (1080–150) keV - cascade yields the mixing ratio =+0.08(4).