The rattling chain model has provided a useful phenomenological guideline for identifying $A{M}_6{X}_6$-type kagome charge density wave (CDW) materials. In this work, we performed a comprehensive experimental and theoretical investigation of ${\text{TiV}}_6{\text{Sn}}_6$, a kagome CDW material predicted by the rattling chain model. However, resistivity, magnetization, and specific heat measurements reveal no evidence of a CDW transition in ${\text{TiV}}_6{\text{Sn}}_6$. Furthermore, unlike its rare-earth-based sister compound $R{\text{V}}_6{\text{Sn}}_6$ ($R$ = Sc, Y, Sm, and Gd-Lu), phonon calculations show that ${\text{TiV}}_6{\text{Sn}}_6$ exhibits no imaginary phonon modes under either compressive or tensile strain. The band structure and crystal orbital Hamilton population (COHP) curves of ${\text{TiV}}_6{\text{Sn}}_6$ exhibit recognizable differences from those of $R{\text{V}}_6{\text{Sn}}_6$. Further analysis attributes these differences to the higher electronegativity of Ti relative to the rare-earth elements. The enhanced electronegativity promotes mixed ionic-covalent bonding, where the covalent character suppresses the rattling motion of Ti, ultimately precluding the formation of a CDW. Our findings suggest that the electronegativity of the filler atom, in addition to its ionic radius, should be incorporated as a supplementary factor into the rattling chain model.

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• Charge density waves
• Electronic structure
• Crystal growth
• First-principles calculations
• Transport techniques