溴化硼分子及离子的势能函数与垂直电离势

为了弄清BBr在金属蚀刻中的机理 ,需了解BBrn(n =0、+ 1、+ 2 )分子及离子体系势能函数和稳定性的信息 ,用原子分子反应静力学原理推导出了BBrn(n =0、+ 1、+ 2 )的基态电子状态及其离解极限 .基于cc pVDZ基组 ,用B3LYP方法计算了他们的平衡几何、电子状态 ,在此基础上分别计算了BBr、BBr+ 的Murrell Sorbie解析势能函数和BBr2 + 的解析势能函数及其对应的力常数、光谱参数 .BBrn(n =+ 1、+ 2 )离子的垂直电离势为 :I+ =9.583 675eV ,I+ + =2 9.3 4 2 3 4eV .计算表明 ,BBr+ 、BBr2 + 的势能曲线均具有对应于稳定平衡结构的极小点 ,说明BBr+ 、BBr2 + 可稳定存在     

CuH~n(n=0,+1,+2)分子及离子的势能函数与垂直电离势(英文)

推导出了CuHn(n=0、+1、+2)的基态电子状态及其离解极限.基于SDD和6-311G**基组,用B3PW91方法计算了他们的平衡几何、电子状态,在此基础上分别计算了CuH,CuH+1的Murrell-Sorbie解析势能函数和CuH+2的解析势能函数及其对应的力常数、光谱参数.CuHn(n=+1,+2)离子的垂直电离势为:I+=-965.00eV,I++=-944.70eV.计算表明CuH+、CuH2+的势能曲线均具有对应于稳定平衡结构的极小点,说明CuH+、CuH2+可稳定存在.     

CrHn(n=0,+1,+2)分子及离子的势能函数

用原子分子反应静力学原理推导出CrHⁿ(n=0，+1，+2)的电子状态及其离解极限. 对H原子采用6-311++G^**基组，对Cr原子采用SVP(split valence polarization)全电子基组，用B3PW91方法计算了它们的平衡几何、电子状态，在此基础上分别计算CrH，CrH⁺的Murrell-Sorbie解析势能函数和CrH²⁺的解析势能函数及其对应的力常数、光谱参数，理论计算值与实验值和文献计算值符合较好. 从离解极限和通道解释了不同的势能函数形状. 计算表明：CrH⁺的势能曲线均具有对应于稳定平衡结构的极小点，说明CrH⁺可稳定存在. 而CrH²⁺离子的势能曲线对应于不稳定的排斥态，说明CrH²⁺是不稳定的. 关键词： n(n=0')" href="#">CrHⁿ(n=0 +2) 势能函数 光谱参数 稳定性     

CrHn(n=0,+1,+2)分子及离子的势能函数

用原子分子反应静力学原理推导出CrHn(n =0,+1,+2)的电子状态及其离解极限.对H原子采用6-311++G**基组,对Cr原子采用SVP(split valence polarization)全电子基组,用B3PW91方法计算了它们的平衡几何、电子状态,在此基础上分别计算CrH, CrH+的Murrell-Sorbie解析势能函数和CrH2+的解析势能函数及其对应的力常数、光谱参数,理论计算值与实验值和文献计算值符合较好.从离解极限和通道解释了不同的势能函数形状.计算表明:CrH+的势能曲线均具有对应于稳定平衡结构的极小点,说明CrH+可稳定存在.而CrH2+离子的势能曲线对应于不稳定的排斥态,说明CrH2+是不稳定的.     

GeHn±(n=0,1,2)的势能函数和光谱常数研究

用密度泛函B3lyp/6-311++g(d,p)方法对 分子离子进行理论研究。结果表明：GeH,GeH+,GeH-1均能稳定存在,GeH+2和GeH-2有亚稳定态存在,其基态电子态分别是: 2Π(GeH),1Σ(GeH+),3Σ(GeH-),2Σ(GeH+2)和2Π(GeH-2),GeH+2和GeH-2的势能函数呈明显的‘火山态’型,导出了相应的分子离子的解析势能函数、光谱数据和力常数,比较了四参数、八参数Murrell-Sorbie势和Zhu-Wang势对不稳定分子势能函数的拟合情况,指出了用八参数Murrell-Sorbie势对‘火山态’型势能函数的拟合也是合适的;同时讨论了电荷对势能函数和能级的影响。     

电荷对Cu2n±(n=0,1,2)分子离子的势能函数和能级的影响

用密度泛函B3LYP /LANL2DZ方法对Cu2n±(n=0,1,2)分子离子进行理论研究.结果表明:Cu2,Cu+2,Cu-2,Cu22-能稳定存在,基电子状态分别是:1Σg+(Cu2),2Σg(Cu2+),2Σu(Cu-2),1Σg(Cu22-),Cu-2和Cu22-的势能函数呈明显的‘火山态' 型.导出了相应的分子离子的解析势能函数、光谱数据和力常数,而Cu22+不能稳定存在;同时讨论了电荷对势能函数和能级的影响.     

用能量自洽法研究双原子分子离子XY+的势能函数

基于能量变分思想,建立了双原子分子离子XY+势能函数的新解析形式--ECMI势.该势函数中的离子库仑作用势包含了各级高阶修正,变分可调且收敛迅速.本文用这种新的解析势能函数和离子的能量自洽法(Energy-consistent-method for ion, ECMI)研究了双原子分子离子CO+基态X2Σ+态的势能函数.结果表明,新的解析势能函数ECMI势更加适合用来描述双原子分子离子XY+的全程势能行为.     

Mg2Ni分子的结构和势能函数

采用密度泛函B3LYP方法在6-311+g(d,p)基组水平上对MgNi、Mg2和Mg2Ni分子的各种可能的结构进行优化,得到了它们的几何构型、平衡核间距、离解能和谐振频率.采用最小二乘法拟合MgNi和Mg2分子的Murrell-Sorbie势能函数,在此基础上导出光谱数据和力常数.通过多体项展式理论导出Mg2Ni分子的解析势能函数,并绘出了Mg2Ni分子的等值势能面,其等值势能面正确地反应了基态Mg2Ni分子的平衡构型特征.     

用能量自洽法研究双原子分子离子XY+的五阶解析势能函数

将用于研究双原子分子离子XY⁺解析势能函数的能量自洽法(energy consistent method for ion XY⁺,ECMI)从三阶推广到五阶,并将双原子分子离子XY⁺的三阶解析势能函数ECMI(3)推广为五阶的解析势能函数ECMI(5),研究CO⁺的B²Σ⁺态和SO⁺的b⁴Σ^-态的解析势能函数.结果表明,CO⁺的B²Σ⁺态和SO⁺的b⁴Σ^-态的新解析势能函数ECMI(5)势与基于实验的RKR数据符合得很好,优于常用的中性双原子分子势能函数Morse势、HMS势和双原子分子离子XY⁺的ECMI(3)势在这两个离子状态下的表现.不仅如此,ECMI势给出了对原子分子碰撞等诸多研究非常重要的正确理解极限和全程势能数据.     

Pu2+2 分子离子的结构与势能函数

使用密度泛函B3LYP方法对Pu2+2分子离子进行了理论研究,结果表明,Pu2+2分子离子是亚稳定结构,基态电子状态为 13Σg,势能函数可以用Z-W函数来表征,并首次计算获得基态分子离子的力常数和光谱数据.     

BH2的分子结构和势能函数

采用密度泛函理论(DFT)的B3P86方法和相对论有效原子实势理论模型(RECP)，对BH₂，BH₂⁺和BH₂^-分子进行了优化，得到这些分子基态的电子状态分别是²A′，³A′，³A″. 计算也得到了BH₂的分子结构和势能函数，它的离解能是7.752eV，BH₂分子具有C_{2V关键词： 2}')" href="#">BH₂ 分子结构 势能函数     

BH2和AlH2分子的结构及其解析势能函数

运用二次组态相关(QCISD)方法，分别选用6-311++G(3df,3pd)和D95(3df,3pd)基组，对BH₂和AlH₂分子的结构进行了优化计算，得到BH₂分子的稳态结构为C_2v构型，电子态为²A₁、平衡核间距R_BH=0.1187nm、键角∠HBH=128.791°、离解能D_e=3.65eV、基态振动频率ν₁(a₁)=1020.103cm^-1,ν₂(a₁)=2598.144cm^-1,ν₃(b₂)=2759.304cm^-1.AlH₂分子的稳态结构也为C_2v构型，电子态为²A₁、平衡核间距R_AlH=0.1592nm、键角∠HAlH=118.095°、离解能D_e=2.27eV、基态振动频率ν₁(a₁)=780.81cm^-1,ν₂(a₁)=1880.81cm^-1，ν₃(b₂)=1910.46cm^-1.采用多体项展式理论推导了基态BH₂和AlH₂分子的解析势能函数，其等值势能图准确再现了BH₂和AlH₂分子的结构特征及其势阱深度与位置.分析讨论势能面的静态特征时得到BH+H→BH₂反应中存在鞍点，活化能为150.204kJ/mol；AlH+H→AlH₂反应中也存在鞍点，活化能为54.8064kJ/mol. 关键词： 2')" href="#">BH₂ 2')" href="#">AlH₂ Murrell-Sorbie函数 多体项展式理论 解析势能函数     

PdCO分子结构与势能函数

用密度泛函理论的B3LYP方法,对钯原子采用LANL2DZ收缩价基函数,碳原子和氧原子采用AUG-cc-pVTZ基组,对PdC,PdO和PdCO体系的结构进行优化,计算表明：PdC分子基态为¹Σ⁺态,键长为R_e=0.17285nm,离解能为4.919eV.PdO分子基态的平衡核间距为0.18546nm,其电子态为³Π,离解能为2.455eV,并拟合得到Murrell-Sorbie势能函数;PdCO分子有两 关键词： PdCO 分子结构 势能函数     

On the spectra luminescence properties of charoite silicate

Charoite is a hydrous alkali calcium silicate mineral [K₄NaCa₇Ba_0.75Mn_0.2Fe_0.05(Si₆O₁₅)₂(Si₂O₇)Si₄O₉(OH)·3(H₂O)] exhibiting an intense lilac colour related to Mn²⁺ and Fe³⁺ colour centres. These ions also contribute to a strong luminescence at ∼585 and 705 nm. This work studies the thermal dependence of these luminescent centres by (i) thermoluminescence (TL) of pre-heated and pre-irradiated charoite aliquots, (ii) by time-resolved cathodoluminescence (TRS-CL) at room and cryogenic temperatures (RT and CT), (iii) by spatially resolved spectra CL under scanning electron microscopy (SRS-CL-SEM) and (iv) by ion beam spectra luminescence (IBL) with H⁺, H₂⁺ and ⁴He⁺ ions at RT and LT. The main peak, ∼585 nm, is linked to a transition ⁴T_1,2 (G)→⁶A₇(S) in Mn²⁺ ions in distorted six-fold coordination and the emission at ∼705 nm with Fe²⁺→Fe³⁺ oxidation in Si⁴⁺ lattice sites. Less intense UV-blue emissions at 340 and 390 nm show multi-order kinetic TL glow curves involving continuous processes of electron trapping and de-trapping along with an irreversible phase transition of charoite by de-hydroxylation and lattice shortening of Δa=0.219 Å, Δb=0.182 Å; Δc=0.739 Å. The Si-O stressed lattice of charoite has non-bridging oxygen or silicon vacancy-hole centres, and Si-O bonding defects which seem to be responsible for the 340 nm emission. Extrinsic defects such as the alkali (or hydrogen)—compensated [AlO₄/M⁺] centres could be linked with the 390 nm emission. Large variations in 585 and 705 nm intensities are strongly temperature dependent, modifying local Fe-O and Mn-O bond distances, short-range-order luminescence centres being very resistant under the action of the heavy ion beam of ⁴He⁺. The SRS-CL demonstrates strong spatial heterogeneity in the luminescence of the charoite.     

Polarized electron capture by3He2+ at 20–28 keV

Nuclear polarization was measured by means of beam foil spectroscopy for a³He⁺ ion produced by an electron capture process of a³He²⁺ from a polarized sodium atom in an incident energy range from 20 to 28 keV. Assuming that a polarized electron of a sodium atom is predominantly captured to the 3d orbital of a³He⁺ ion andcascades down to the 1s ground state via the 2p orbital, an alignment factorA ₀ ^col (L=2) for the 3d orbital of a³He⁺ ion was extracted by comparing the observed initial sodium polarization andfinal nuclear polarization. The observedA ₀ ^col (L=2) showed a less pronounced energy dependence andwere qualitatively reproduced by the theoretical calculation.     

Universal basis of two-center functions. test computations of certain diatomic molecules and ions

It is shown that the basis of two-center functions is universal. The dependence of the nuclei of atoms comprising a molecule on charges and on the intranuclear spacing is separated explicitly in the integrals used in analyzing diatomic molecules. The basis integrals constructed once permitted rapid and effective execution of computations for the ground state potential curves for a number of electron systems: H₂, He₂ ²⁺, HeH⁺, He₂, LiH, Li₂, HeB⁺, Be₂.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 11, pp. 74–79, November, 1986.     

A variable temperature EPR study of the manganites (La1/3Sm2/3)2/3SrxBa0.33−xMnO3 (x=0.0, 0.1, 0.2, 0.33): Small polaron hopping conductivity and Griffiths phase

Four manganite samples of the series, (La_1/3Sm_2/3)_2/3Sr_xBa_0.33−xMnO₃, with x=0.0, 0.1, 0.2 and 0.33, were investigated by X-band (∼9.5 GHz) electron paramagnetic resonance (EPR) in the temperature range 4-300 K. The temperature dependences of EPR lines and linewidths of the samples with x=0.0, 0.1 and 0.2, containing Ba²⁺ ions, exhibit similar behavior, all characterized by the transition temperatures (T_C) to ferromagnetic states in the 110-150 K range. However, the sample with x=0.33 (containing no Ba²⁺ ions) is characterized by a much higher T_C=205 K. This is due to significant structural changes effected by the substitution of Ba²⁺ ions by Sr²⁺ ions. There is an evidence of exchange narrowing of EPR lines near T_min, where the linewidth exhibits the minimum. Further, a correlation between the temperature dependence of the EPR linewidth and conductivity is observed in all samples, ascribed to the influence of small-polaron hopping conductivity in the paramagnetic state. The peak-to-peak EPR linewidth was fitted to ΔB_pp(T)=ΔB_pp,min+A/Texp(−E_a/k_BT), with E_a=0.09 eV for x=0.0, 0.1 and 0.2 and E_a=0.25 eV for x=0.33. From the published resistivity data, fitted here to σ(T)∝1/T exp(−E_σ/k_BT), the value of E_σ, the activation energy, was found to be E_σ=0.18 eV for samples with x=0.0, 0.1 and 0.2 and E_σ=0.25 eV for the sample with x=0.33. The differences in the values of E_a and E_σ in the samples with x= 0.0, 0.1and 0.2 and x=0.33 has been ascribed to the differences in the flip-flop and spin-hopping rates. The presence of Griffiths phase for the samples with x=0.1 and 0.2 is indicated; it is characterized by coexistence of ferromagnetic nanostructures (ferrons) and paramagnetic phase, attributed to electronic phase separation.     

Fe-site assignments in Y1Ba2Cu3O7 revisited

A new symmetric Fe³⁺ site (labelled E) (δ=0.28(2) mm/s and Δ=0.15 mm/s) is observed in the R₁Ba₂Cu₃O₇ family of superconductors for R=Y and Eu. The decay and growth of site E are established in two seemingly unrelated experiments, one as a function of room temperature aging for R=Y, and the other as a function of oxygen loading at elevated temperatures and pressures for R=Eu. In each experiment, the results show that site E is genetically related to the well documented chainsites A(Δ=1.9 mm/s), C(Δ=1.1 mm/s) and D(Δ=1.6 mm/s). We propose that site E represents a quasi-octahedral chain-site having pairs of O(1), O(4) and O(5) nearestneighbor oxygen sites. The two remaining doublets, B(Δ≈0.4 mm/s) and B′(Δ=0.78 mm/s) represent Fe³⁺ dopant sites present in the all-important CuO₂ planes, possessing coordination numbers of 6 and 5, respectively.     

Electronic absorption spectrum of CO+ in an ion beam

The He+He⁺¹ interactions have been studied, as a function of the internuclear separation R, in terms of the electronic forces acting on the nuclei and the change in the charge distribution. The analysis reveals that at large R the atomic densities are polarized inwards, causing an attractive force on each nucleus, while at small R the difference in the nature of the interactions in the ²Σ_u and ²Σ_g systems is noted. It is seen that the He+He⁺¹ (²Σ_u) interaction is less attractive than the He⁺¹+He⁺¹ interaction at lower values of R.     

X-Ray induced enhancement effect in electroluminescent zinc sulphides

Enhancement effect in electroluminescent emission from ZnS∶Cu, Cl and ZnS∶Cu, Mn, Cl luminophors under the concurrent action of sinusoidal electric field and x-radiation has been investigated. Variation of the enhancement ratioR=B _E+R/B_E+B_R whereB _E+R =Light output when both electric field and x-radiation are operative;B _E=Electroluminescent output;B _R=Photoluminescent output with frequency and voltage of the applied A.C. field and with x-ray intensity has been studied. A non-linear behaviour of the enhancement with voltage and x-ray intensity has been found, which is similar to that observed in the case of ultraviolet stimulated electroluminescent emission. R _max in both the species studied, is always found to be less than 4/3 in each case.