Semiempirical parametrization of energy-level data

2003 ◽  
pp. 42-71
Keyword(s):  
2020 ◽  
Vol 499 (1) ◽  
pp. 25-39
Author(s):  
Anna-Maree Syme ◽  
Laura K McKemmish

ABSTRACT The cyano radical (CN) is a key molecule across many different factions of astronomy and chemistry. Accurate, empirical rovibronic energy levels with uncertainties are determined for eight doublet states of CN using the marvel (Measured Active Rotational-Vibrational Energy Levels) algorithm. 40 333 transitions were validated from 22 different published sources to generate 8083 spin-rovibronic energy levels. The empirical energy levels obtained from the marvel analysis are compared to current energy levels from the mollist line list. The mollist transition frequencies are updated with marvel energy level data which brings the frequencies obtained through experimental data up to 77.3 per cent from the original 11.3 per cent, with 92.6 per cent of the transitions with intensities over 10−23 cm molecule−1 at 1000 K now known from experimental data. At 2000 K, 100.0 per cent of the partition function is recovered using only marvel energy levels, while 98.2 per cent is still recovered at 5000 K.


1997 ◽  
Vol 56 (3) ◽  
pp. 240-244 ◽  
Author(s):  
L J Curtis ◽  
D G Ellis ◽  
R Matulioniene ◽  
T Brage

1979 ◽  
Vol 17 (1) ◽  
pp. 56-60
Author(s):  
W.C. Martin

The ongoing program of the Atomic Energy Levels Data Center (National Bureau of Standards) to produce new compilations of critically evaluated energy level data is at present focused on the first thirty elements. The most recently completed compilations in this series give energy levels for all the spectra of Mn (Mn I-XXV) (1), Cr (Cr I-XXIV) (2), V (V I-XXIII) (3), Ti (Ti I-XXII) (4),Ca (Ca I-XX) (5), and Al (Al I-XIII) (6), and work is underway on the spectra of K and Mg. C.E. Moore’s “Selected Tables of Atomic Spectra” now include 0 1 (7), 0 VI, O VII, and O VIII (8), work on the tables for the remaining oxygen spectra is in progress. A finding list for lines of the multiplets in Sections 1-7 of Moore’s NSRDS-NBS 3 series has been compiled by Adelman et al. (9). A recent publication of the AEL Data Center, “Atomic Energy Levels - The Rare-Earth Elements” (10), gives energy-level data for 66 spectra of the 15 elements La through Lu (Z=57-71), including a number of astronomically important spectra. A review of rare-earth spectral data by Blaise et al. (11) gives partial tables of energy levels and wavelengths and includes data on hyperfine-structure and isotope shifts. The first version of a much needed new compilation of “Line Spectra of the Elements” has recently been published (12). These tables contain some 42,000 lines, including the stronger lines of the first and second spectra of 98 elements and lines of the third, fourth, and fifth spectra for about half the elements from the vacuum ultraviolet to the far infrared. Outred (13) has compiled 8885 selected lines of 57 elements in the infrared region 1-4 pm, with energy-level classifications being given where available. Energy-level and Grotrian diagrams for the atoms and positive ions of the elements H through P (Z=l-15) have been prepared by Bashkin and Stoner (14), and further publications for the heavier elements are planned. The AEL Data Center (NBS) expects to publish in 1979 a “Bibliography on Atomic Energy Levels and Spectra” for the period July 1975 through December 1978 (15). Edlen’s 1976 review of term analysis of atomic spectra has references for spectra of the elements He through Ni (16), and Adelman et al. (17) have compiled an astronomically oriented bibliography on atomic autoionization. A bibliography on experimental isotope shifts in atomic spectra by Heilig (18) gives 666 references.


2017 ◽  
Vol 33 (3) ◽  
pp. 181-189 ◽  
Author(s):  
Christoph J. Kemper ◽  
Michael Hock

Abstract. Anxiety Sensitivity (AS) denotes the tendency to fear anxiety-related sensations. Trait AS is an established risk factor for anxiety pathology. The Anxiety Sensitivity Index-3 (ASI-3) is a widely used measure of AS and its three most robust dimensions with well-established construct validity. At present, the dimensional conceptualization of AS, and thus, the construct validity of the ASI-3 is challenged. A latent class structure with two distinct and qualitatively different forms, an adaptive form (normative AS) and a maladaptive form (AS taxon, predisposing for anxiety pathology) was postulated. Item Response Theory (IRT) models were applied to item-level data of the ASI-3 in an attempt to replicate previous findings in a large nonclinical sample (N = 2,603) and to examine possible interpretations for the latent discontinuity observed. Two latent classes with a pattern of distinct responses to ASI-3 items were found. However, classes were indicative of participant’s differential use of the response scale (midpoint and extreme response style) rather than differing in AS content (adaptive and maladaptive AS forms). A dimensional structure of AS and the construct validity of the ASI-3 was supported.


Methodology ◽  
2018 ◽  
Vol 14 (3) ◽  
pp. 95-108 ◽  
Author(s):  
Steffen Nestler ◽  
Katharina Geukes ◽  
Mitja D. Back

Abstract. The mixed-effects location scale model is an extension of a multilevel model for longitudinal data. It allows covariates to affect both the within-subject variance and the between-subject variance (i.e., the intercept variance) beyond their influence on the means. Typically, the model is applied to two-level data (e.g., the repeated measurements of persons), although researchers are often faced with three-level data (e.g., the repeated measurements of persons within specific situations). Here, we describe an extension of the two-level mixed-effects location scale model to such three-level data. Furthermore, we show how the suggested model can be estimated with Bayesian software, and we present the results of a small simulation study that was conducted to investigate the statistical properties of the suggested approach. Finally, we illustrate the approach by presenting an example from a psychological study that employed ecological momentary assessment.


2013 ◽  
Author(s):  
Robert E. Thayer ◽  
Olga Godes ◽  
Nicole E. Lobato ◽  
Marcelino Serrano ◽  
Jorge Hernandez ◽  
...  
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