Equivalent exploitation of four-pulse one-dimensional ESEEM and HYSCORE spectroscopies for the elucidation of BOHC defects in borate glasses supported by quantum mechanical calculations

B₂O₃-Li₂O glass was exposed to ⁶⁰Co {γ} irradiation and measured with four-pulse (4P) one-dimensional (1D) electron spin echo envelop modulation (ESEEM) spectroscopy and hyperfine sublevel correlation (HYSCORE) spectroscopy. 4P 1D ESEEM revealed the values of χzz<~0.7MHz, η~0.4Tₐₙᵢₛₒ<~0.8MHz, and Aᵢₛₒ~0.6MHz for the second boron neighbor. In a- and c-B₂O₃, 4P 1D ESEEM uncovered the value of χzz~2.6MHz for the second boron neighbor. HYSCORE spectroscopy in the B₂O₃-Li₂O glass revealed a weak coupling with χzz<~0.7MHz, η~0.37, Tₐₙᵢₛₒ<~0.9MHz, and Aᵢₛₒ<~0.9MHz due to the interaction of the spin with the second boron neighbor loosely bonded with the defect. An orthoborate group in the proximity of fourfold coordinated boron cluster reproduces the experimental parameters most satisfactorily.