Orientational anisotropy of photoemitting CS₂ molecules induced by molecular field splitting

Abstract We recorded the sulfur 2 p photoelectron spectrum from gas-phase CS 2 molecules, in coincidence with the ionic fragments S + , S 2+ and CS + . The fragments are created by the dissociation of the parent molecular dication following the Auger decay of the S 2 p vacancy. The S 2 p photoelectrons were recorded in the direction of the polarization vector of synchrotron radiation at FinEstBeAMS beamline of MAX IV synchrotron, using a hemispherical energy analyzer with sufficiently high resolution to resolve the molecular field splitting effects. The coincident ionic fragments of the linear molecule provided the orientation of the molecular axis of molecules emitting electrons in the polarization direction along the polarization vector of the incident photon beam and we obtained the orientation distributions of these molecules for photoemission from the three spin–orbit and molecular field split components in the S 2 p orbital. The molecular field splitting introduced clear differences in the measured orientation distributions. Photoemission along the polarization vector from the 2 p orbital with <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mi>j</mml:mi> <mml:mo>=</mml:mo> <mml:mrow> <mml:mpadded depth="-2.8pt" height="+2.8pt"> <mml:mstyle displaystyle="false" scriptlevel="0"> <mml:mrow> <mml:mn>1</mml:mn> </mml:mrow> </mml:mstyle> </mml:mpadded> </mml:mrow> <mml:mstyle scriptlevel="0"/> <mml:mrow> <mml:mo>/</mml:mo> </mml:mrow> <mml:mstyle scriptlevel="0"/> <mml:mrow> <mml:mpadded depth="+1.8pt" height="-1.8pt"> <mml:mstyle displaystyle="false" scriptlevel="0"> <mml:mrow> <mml:mstyle displaystyle="false" scriptlevel="1"> <mml:mn>2</mml:mn> </mml:mstyle> </mml:mrow> </mml:mstyle> </mml:mpadded> </mml:mrow> <mml:mo>,</mml:mo> <mml:msub> <mml:mi>m</mml:mi> <mml:mi>j</mml:mi> </mml:msub> <mml:mo>=</mml:mo> <mml:mo>±</mml:mo> <mml:mrow> <mml:mpadded depth="-2.8pt" height="+2.8pt"> <mml:mstyle displaystyle="false" scriptlevel="0"> <mml:mrow> <mml:mn>1</mml:mn> </mml:mrow> </mml:mstyle> </mml:mpadded> </mml:mrow> <mml:mstyle scriptlevel="0"/> <mml:mrow> <mml:mo>/</mml:mo> </mml:mrow> <mml:mstyle scriptlevel="0"/> <mml:mrow> <mml:mpadded depth="+1.8pt" height="-1.8pt"> <mml:mstyle displaystyle="false" scriptlevel="0"> <mml:mrow> <mml:mstyle displaystyle="false" scriptlevel="1"> <mml:mn>2</mml:mn> </mml:mstyle> </mml:mrow> </mml:mstyle> </mml:mpadded> </mml:mrow> </mml:mrow> </mml:math> created the most isotropic distribution of the emitter molecules, while the distribution corresponding to the 2 p orbital with <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mi>j</mml:mi> <mml:mo>=</mml:mo> <mml:mrow> <mml:mpadded depth="-2.8pt" height="+2.8pt"> <mml:mstyle displaystyle="false" scriptlevel="0"> <mml:mrow> <mml:mstyle displaystyle="false" scriptlevel="1"> <mml:mn>3</mml:mn> </mml:mstyle> </mml:mrow> </mml:mstyle> </mml:mpadded> </mml:mrow> <mml:mstyle scriptlevel="0"/> <mml:mrow> <mml:mo>/</mml:mo> </mml:mrow> <mml:mstyle scriptlevel="0"/> <mml:mrow> <mml:mpadded depth="+1.8pt" height="-1.8pt"> <mml:mstyle displaystyle="false" scriptlevel="0"> <mml:mrow> <mml:mstyle displaystyle="false" scriptlevel="1"> <mml:mn>2</mml:mn> </mml:mstyle> </mml:mrow> </mml:mstyle> </mml:mpadded> </mml:mrow> <mml:mo>,</mml:mo> <mml:msub> <mml:mi>m</mml:mi> <mml:mi>j</mml:mi> </mml:msub> <mml:mo>=</mml:mo> <mml:mo>±</mml:mo> <mml:mrow> <mml:mpadded depth="-2.8pt" height="+2.8pt"> <mml:mstyle displaystyle="false" scriptlevel="0"> <mml:mrow> <mml:mstyle displaystyle="false" scriptlevel="1"> <mml:mn>3</mml:mn> </mml:mstyle> </mml:mrow> </mml:mstyle> </mml:mpadded> </mml:mrow> <mml:mstyle scriptlevel="0"/> <mml:mrow> <mml:mo>/</mml:mo> </mml:mrow> <mml:mstyle scriptlevel="0"/> <mml:mrow> <mml:mpadded depth="+1.8pt" height="-1.8pt"> <mml:mstyle displaystyle="false" scriptlevel="0"> <mml:mrow> <mml:mstyle displaystyle="false" scriptlevel="1"> <mml:mn>2</mml:mn> </mml:mstyle> </mml:mrow> </mml:mstyle> </mml:mpadded> </mml:mrow> </mml:mrow> </mml:math> was preferredly perpendicular to the polarization vector. Emission from the 2 p orbital with <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mi>j</mml:mi> <mml:mo>=</mml:mo> <mml:mrow> <mml:mpadded depth="-2.8pt" height="+2.8pt"> <mml:mstyle displaystyle="false" scriptlevel="0"> <mml:mrow> <mml:mstyle displaystyle="false" scriptlevel="1"> <mml:mn>3</mml:mn> </mml:mstyle> </mml:mrow> </mml:mstyle> </mml:mpadded> </mml:mrow> <mml:mstyle scriptlevel="0"/> <mml:mrow> <mml:mo>/</mml:mo> </mml:mrow> <mml:mstyle scriptlevel="0"/> <mml:mrow> <mml:mpadded depth="+1.8pt" height="-1.8pt">