Li₂B₄O₇ crystal structure was studied at elevated temperatures and refined in anharmonic approximation: 20 °C, a = 9.475(3), c = 10.283(6) Å, 883 F(h k l), R = 0.015; 200 °C, a = 9.501(3), c = 10.275(6) Å, 826 F(h k l), R = 0.021; 400 °C, a = 9.535(3), c = 10.295(8) Å, 809 F(h k l), R = 0.022; and 500 °C, a = 9.550(3), c = 10.295(6) Å, 779 F(h k l), R = 0.029. B{single bond}O bond lengths were corrected in a view of O and B atomic vibrations. Refinement of anharmonic components of atomic temperature factors has revealed high asymmetry of Li thermal vibrations. The behaviour of tetraborate groups was studied. A stability of rigid B{single bond}O groups configuration was indicated, as in the case of β{single bond}CsB₅O₈, LiB₃O₅ and β-Na₂B₈O₁₃, studied by us earlier. The boron-oxygen framework expands as a three-dimensional hinge; B{single bond}O{single bond}B and O{single bond}B{single bond}O angles inside tetraborate groups practically do not change, while B1{single bond}O1{single bond}B2 angles between the groups increase to 1.6° on heating up to 500 °C due to O1 atoms shifts letting Li atom to fall through oxygen atoms along c-axis causing the contraction in this direction.