*3.4. NQR Measurements*

The powdered sample without further preparation was placed in a standard 5 mm glass sample tube, which was subsequently placed inside the probe of the NQR spectrometer. 35 Cl NQR spectra were recorded using NMR/NQR Tecmaq Redstone spectrometer

by the single pulse method in the frequency range 35–37 MHz. The pulse duration was 3 μs, followed by 1 ms acquisition and subsequent 400 ms delay time. The number of scans was ca. 3000. The temperature was controlled using an Oxford Instrument cryostat and stabilized with the precision better than ±1 K.
