Theoretical spectroscopic parameters are derived for all isotopologues of HCO⁺ and HOC⁺ involving H, D, ¹⁶O, ¹⁷O, ¹⁸O, ¹²C, and ¹³C by means of a two-step procedure. Full-dimensional rovibrational calculations are first carried out to obtain numerically exact rovibrational energies for J = 0–15 in both parities. Effective spectroscopic constants for the vibrational ground state, ν₁, ν₂, and ν₃ are determined by fitting the calculated rovibrational energies to appropriate spectroscopic Hamiltonians. Combining our vibration-rotation corrections with the available experimental ground-state rotational constants, we also derive the new estimate for the equilibrium structure of HCO⁺, r_e(CH) = 1.091 98 Å and r_e(CO) = 1.105 62 Å, and for the equilibrium structure of HOC⁺, r_e(HO) = 0.990 48 Å and r_e(CO) = 1.154 47 Å. Regarding the spectroscopic parameters, our estimates are in excellent agreement with available experimental results for the isotopic variants of both HCO⁺ and HOC⁺: the agreement for the rotational constants $B_v$ is within 3 MHz, for the quartic centrifugal distortion constants $D_v$ within 1 kHz, and for the effective $\ell$-doubling constants $q_v$ within 2 MHz. We thus expect that our results can provide useful assistance in analyzing expected observations of the rare isotopologues of HCO⁺ and HOC⁺ that are not yet experimentally known.

中文翻译：

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HCO ⁺和HOC ⁺同位素变体的理论光谱参数

通过两个步骤，得出了涉及H，D，¹⁶ O，¹⁷ O，¹⁷ O，¹⁸ O，¹² C和¹³ C的HCO ⁺和HOC ^+的所有同位素的理论光谱参数。首先进行全尺寸的旋转振动计算，以在两个奇偶校验中获得J = 0-15的数值精确的旋转振动能量。为振动基态有效光谱常数，ν ₁，ν ₂，和ν ₃通过将计算出的旋转振动能量与适当的光谱哈密顿量拟合来确定。将我们的振动-旋转校正与可用的实验基态旋转常数相结合，我们还得出了HCO ⁺的平衡结构的新估计值，r _e（CH）= 1.091 98Å和r _e（CO）= 1.105 62Å，对于HOC ⁺的平衡结构，r _e（HO）= 0.990 48Å和r _e（CO）= 1.154 47Å。关于光谱参数，我们的估计与HCO ⁺和HOC ⁺同位素变体的可用实验结果非常吻合：旋转常数的一致性 ${乙}_v$ 对于四次离心畸变常数，在3 MHz以内 $d_v$ 在1 kHz以内 $\ell$常数加倍 $q_v$2 MHz以内。因此，我们希望我们的结果可以为分析HCO ⁺和HOC ⁺的稀有同位素的预期观测结果提供有用的帮助，而这些实验尚不为人所知。