"Society has arisen out of the works of peace; the essence of society is peacemaking. Peace and not war is the father of all things." Ludwig von Mises, 1922

From January 25 to January 27, 2023, ICONS-6, the sixth edition of the Konstantin Ivanov InterCONtinental Magnetic Resonance Seminar, an on-line magnetic resonance conference series named after our untimely deceased colleague and friend Konstantin L’vovich Ivanov (Kostya), took place. The ICONS conferences and the weekly Intercontinental NMR Seminar Series that started on April 8, 2020, have given nearly 200 speakers a platform to disseminate their scientific results to a broad international audience from 6 continents. While the weekly seminar series gives both early-stage and experienced researchers an opportunity to give talks in an international environment and interact with colleagues from all over the world, the ICONS conference is a platform where experienced researchers present their results. The ICONS-6 conference attracted registrations from nearly 250 people from 20 countries (in the spirit of the meeting, covering 6 continents, Europe, North America, South America, Africa, Australia, and Asia) and spanned time zones from Japan over Europe to the US West Coast. The meeting talks were broadcast across the Zoom and YouTube platforms. The average combined attendance was around 120.

The ICONS seminar series is open to all areas of magnetic resonance and covers the full range of magnetic resonance, i.e., EPR, NMR, MRI, and their various hybrids. While the summer ICONS conferences (see reports in APMR [1,2,3] for details) are equally broad in scope as the seminars, the spring conferences are focused on a narrower subject, such as techniques, where the interaction of electron and nuclear spins plays a pivotal role (ICONS-2) [4] for details or the various flavors of hyperpolarization and NMR signal enhancement (ICONS-4) [5].

The main goal of ICONS-6 was to present an overview about the current state-of-the-art of various fields of magnetic resonance on solid samples and stimulate interactions among groups employing these techniques in EPR, NMR, and MRI. This main line of the meeting was supplemented by a number of fascination talks discussing cutting edge applications of magnetic resonance in cell-research and archeology. To achieve this goal, 12 speakers were selected among the leading experts in these fields and invited to report at the conference.

Bernd Reif Germany, gave an overview about recent developments in the field of studies of amyloid fiber formation and the underlying aggregation kinetics by a combination of solution and solid-state NMR spectroscopy, revealing the initial steps of the aggregation in the form of a partial denaturization of the native protein, followed by folding into a globular structure and conversion into amyloid fibers.

Nir Bar-Gill Israel, reported on recent progress in their efforts to utilize nitrogen vacancy (NV) centers in diamonds in quantum technology, for contrast enhancement in imaging, as sensors for detecting magnetic resonance, for the creation of hyperpolarization, and the development of new pulse sequences which employ these NV centers.

Laurent Binet France, gave a fascinating overview about the application of EPR spectroscopy for the investigation of mummification balms. The latter are a complex mixture consisting, in general, of beeswax, pine resins, fats, bitumen. In their experiments, they employ endogenous spin probes (vanadyl complexes and aromatic radicals) present in the balm, to characterize the bitumen component and elucidate spectroscopic fingerprints to identify possible origins of the bitumen.

Lyndon Emsley Switzerland, reported on new cutting edge, one- and two-dimensional solid-state NMR experiments to obtain pure isotropic proton (PIP) 1H-NMR spectra of solid samples, based on recent developments in the field of artificial intelligence. He showed that by the utilization of machine-learning techniques, it is possible to produce 1H solid-state NMR with ultra-high resolution.

Sharon Ashbrook UK, discussed novel cost-efficient strategies for the 17O isotope enrichment of inorganic solids and the application potential of 17O solid-state NMR for the investigation of structure, disorder, and chemical reactivity in ceramics, zeolite frame works, and mixed-metal metal organic frameworks (MOFs).

Wiktor Koźmiński Poland, introduced high-dimensional NMR spectroscopy with up to six independent spectral dimensions, the principles of non-uniform sampling as a prerequisite for taming the acquisition times in these types of NMR spectroscopy and applications of these techniques in biomolecular NMR of protein solutions.

Herve Vezin France, gave a fascinating overview in the study of paramagnetic intermediates in battery materials using in situ and in-operando EPR spectroscopy and their interpretation by theoretical calculations to reveal the active REDOX states and their underlying electrochemistry.

Jeffrey Reimer USA, discussed the potential and cost-effectiveness of carbon capture by adsorption onto surfaces of porous materials as a means to mitigate anthropogenic emissions of carbon into the atmosphere. He studied the surface interactions of the CO2 as a function of water content, temperature, gas composition, and pressure with solid-state NMR. From the analysis of these spectra, a detailed molecular understanding of the physisorbed or chemisorbed gas is obtained. This knowledge can aid in the design of novel porous adsorbents, amenable for studies in pilot studies.

Daniella Goldfarb Israel, compared the application potential of two different approaches for distances measurements by pulsed EPR spectroscopy for structural studies of proteins in frozen cell solutions. While the DEER (PELDOR) technique is well-suited for distances above 1.8 nm, the Mims ENDOR (electron-nuclear double resonance) technique is advantageous for shorter distances below this value. She demonstrated the power of the Mims ENDOR experiment on two different frozen protein solutions, namely fluorinated immunoglobulin G-binding protein (GB1) and ubiquitin (Ub), spin-labeled with rigid Gd(III) tags that were introduced into human cells via electroporation.

Matthias Ernst Switzerland, gave a profound introduction into the limits of the achievable proton line-width in high-resolution solid-state MAS NMR spectroscopy of strongly dipolar-coupled proton spin systems. He discussed homonuclear decoupling schemes such as frequency switched Lee Goldburg decoupling or spin-echo detection and the effects of the B1-field inhomogeneity on the line-width. Based on this discussion, he showed how it is feasible to increase the inhomogeneity by means of B1-field selective pulses, which cause an effective reduction of the active sample volume and showed the implementation of the approach in novel pulse sequences.

Teressa Carlomagno UK, reported on recent results in the field of structure determination of nucleic acids and ribonucleoprotein complexes, employing high-resolution solid-state NMR spectroscopy. Employing a combination of 13C and 15N ssNMR with ultrafast 1H-MAS NMR, respectively, 1H-detection causes strong improvements of the spectral resolution in these systems, which permits complete resonance assignments in such elaborate multidimensional experiments as 4D HCCH-TROSY-ssNMR or 4D-HNCH-ssNMR.

Sophia Hayes USA, discussed the application of optically pumped NMR for the characterization of GaAs semiconductor. She showed that by variation of the laser wavelength or polarization, she can address different electronic states in the semiconductor. As these states are coupled via hyperfine interaction to the nuclear spins, an optically pumped nuclear magnetic resonance (OPNMR) signal is created, whose line positions depend on those parameters. Thus, they are indirect monitors of the electronically excited states.

Organization and future developments The conference was organized by Daniel Abergel (ENS Paris, France), Gerd Buntkowsky (TU, Darmstadt, Germany), and P. K. Madhu (TIFR Hyderabad, India). Suman Saurav, TIFR Hyderabad, provided technical assistance. The conference and seminar series were sponsored by Alexander von Humboldt Foundation, Wiley, Springer, HyperSpin, and Adani. For updates and the schedule of upcoming talks and the ICONS7 in summer of 2023, see the home page of the meeting ICONS-Seminar.