J/A+A/657/A55ivo://CDS.VizieR/J/A+A/657/A55doi:10.26093/cds/vizier.36570055CDSSantander C.Denis-Alpizar O.Cardenas C.2022-03-21T09:24:59Z2022-01-06T13:07:28ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.fratomic-physicsAn accurate analysis of the physical-chemical conditions in the regions of the interstellar medium in which C_3_ is observed requires knowing the collisional rate coefficients of this molecule with He, H_2_, electrons, and H. The main goals of this study are to present the first potential energy surface for the C_3_ +H_2_ complex, to study the dynamics of the system, and to report a set of rate coefficients at low temperature for the lower rotational states of C_3_ with para- and ortho-H_2_. Methods. A large grid of ab initio energies was computed at the explicitly correlated coupled-cluster with single-, double-, and perturbative triple-excitation level of theory, together with the augmented correlation-consistent quadruple zeta basis set (CCSD(T)-F12a/aug-cc-pVQZ). This grid of energies was fit to an analytical function. The potential energy surface was employed in close- coupling calculations at low collisional energies. We present a high-level four-dimensional potential energy surface (PES) for studying the collision of C_3_ with H_2_ . The global minimum of the surface is found in the linear HH-CCC configuration. Rotational deexcitation state-to-state cross sections of C_3_ by collision with para- and ortho-H_2_ are computed. Furthermore, a reduced two-dimensional surface is developed by averaging the surface over the orientation of H_2_. The cross sections for the collision with para-H_2_ using this approximation and those from the four-dimensional PES agree excellently. Finally, a set of rotational rate coefficients for the collision of C_3_ with para- and ortho-H_2_ at low temperatures are reported.2022A&A...657A..55Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/657/A55CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/657/A55https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/657/A55http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/657/A55https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/657/A55https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/657/A55http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/657/A55GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/A+A/657/A55/table5Rotational rate coefficients of C_3_ by collision with para-H_2_recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintjiInitial rotational statephys.atmol.initialintjfFinal rotational statephys.atmol.finalint5KCollision rates for T=5K, in cm^3^/molecule/scm**3.mol**-1.s**-1arith.rate;phys.atmol.collisionaldouble10KCollision rates for T=10K, in cm^3^/molecule/scm**3.mol**-1.s**-1arith.rate;phys.atmol.collisionaldouble15KCollision rates for T=15K, in cm^3^/molecule/scm**3.mol**-1.s**-1arith.rate;phys.atmol.collisionaldouble20KCollision rates for T=20K, in cm^3^/molecule/scm**3.mol**-1.s**-1arith.rate;phys.atmol.collisionaldouble25KCollision rates for T=25K, in cm^3^/molecule/scm**3.mol**-1.s**-1arith.rate;phys.atmol.collisionaldouble30KCollision rates for T=30K, in cm^3^/molecule/scm**3.mol**-1.s**-1arith.rate;phys.atmol.collisionaldouble40KCollision rates for T=40K, in cm^3^/molecule/scm**3.mol**-1.s**-1arith.rate;phys.atmol.collisionaldouble50KCollision rates for T=50K, in cm^3^/molecule/scm**3.mol**-1.s**-1arith.rate;phys.atmol.collisionaldoubleJ/A+A/657/A55/table6Rotational rate coefficients of C_3_ by collision with ortho-H_2_recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintjiInitial rotational statephys.atmol.initialintjfFinal rotational statephys.atmol.finalint5KCollision rates for T=5K, in cm^3^/molecule/scm**3.mol**-1.s**-1arith.rate;phys.atmol.collisionaldouble10KCollision rates for T=10K, in cm^3^/molecule/scm**3.mol**-1.s**-1arith.rate;phys.atmol.collisionaldouble15KCollision rates for T=15K, in cm^3^/molecule/scm**3.mol**-1.s**-1arith.rate;phys.atmol.collisionaldouble20KCollision rates for T=20K, in cm^3^/molecule/scm**3.mol**-1.s**-1arith.rate;phys.atmol.collisionaldouble25KCollision rates for T=25K, in cm^3^/molecule/scm**3.mol**-1.s**-1arith.rate;phys.atmol.collisionaldouble30KCollision rates for T=30K, in cm^3^/molecule/scm**3.mol**-1.s**-1arith.rate;phys.atmol.collisionaldouble40KCollision rates for T=40K, in cm^3^/molecule/scm**3.mol**-1.s**-1arith.rate;phys.atmol.collisionaldouble50KCollision rates for T=50K, in cm^3^/molecule/scm**3.mol**-1.s**-1arith.rate;phys.atmol.collisionaldouble